Programming Journal C#, Java, SQL

Installing Web Profile Generator on ASP.NET 3.5

2009-08-25T18:02:00.000-07:00

I finally figure out how to do this. Unfortunately the technical writers were out to lunch when the tried to explain this. Here is my explanation on how to accomplish this in ASP.NET 3.5:

http://weblogs.asp.net/joewrobel/archive/2008/02/03/web-profile-builder-for-web-application-projects.aspx

Install the MSI.
Add (under the other Imports), the <Import Project="$(MSBuildExtensionsPath)\WebProfileBuilder\WebProfileBuilder.targets" />](without []) line to the "MyProject.csproj" file (NOT the user project file, but the one without an extension on Vista) where MyProject is your Web Application Project name.
Add an App_Code folder to your project.
Add the WebProfile.cs file (rt. clicking folder and add existing item)
Rt. click the WebProfile.cs file and click properties.
Change its Build Action from Content to Compile.

Add the profile tags to the web.config file: e.g.

Now you are set. Just make a call to your Profile by setting up this method:

public static WebProfile Profile
{
//get { return new WebProfile(HttpContext.Current.Profile); }
get { return WebProfile.Current; }
}

It should be noted that when you change the Profile, you will need to remove the class from the App_Code and add the newly generated WebProfile.cs class as before.

How to disable Internet Explorer 8 From Installing With Automatic Updates

2009-08-23T09:26:00.000-07:00

To disable Internet Explorer 8 From Installing With Automatic Updates follow these directions:
Download the file from the link below and run.

References:

http://www.microsoft.com/downloads/thankyou.aspx?familyId=21687628-5806-4ba6-9e4e-8e224ec6dd8c&displayLang=en

Use log4net to Log Errors or Visitors

2009-08-15T22:34:00.000-07:00

log4net is a free utility that can be used for logging data about errors or visitors. It is available here: http://logging.apache.org/log4net/index.html

Here is an introductory article: http://www.codeproject.com/KB/trace/Log4Net_with_ASP_NET.aspx

I think a useful way to track users is to log users by their IP Address. Once your log4net is installed correctly, the following code in the Page_Load event can be used to write IP Addresses to a file placed in the App_Code folder (where it is not public):


        if (!Page.IsPostBack)
        {
            string nowip;
            nowip = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
            if (nowip == null)
            {
                nowip = Request.ServerVariables["REMOTE_ADDR"];
            }
            log.Info("Visitor IP: " + nowip);
        }

I'll include the BasePage for a reference to the log variable above (which the System.Web.Page inherits from):


using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using log4net;

public class BasePage : System.Web.UI.Page
{
    public static readonly ILog log = LogManager.GetLogger("Logger");
    public BasePage()
    {
        initLog4Net();
        //logAll();
    }
    /// <summary>
    /// initializes Log4Net 
    /// Described at http://www.codeproject.com/KB/trace/Log4Net_with_ASP_NET.aspx
    /// configured in web.config
    ///     level value can be ALL ERROR DEBUG FATAL DEBUG OFF WARN
    /// </summary>
    private void initLog4Net()
    {
        log4net.Config.XmlConfigurator.Configure();
    }
    /// <summary>
    /// test log4net
    /// </summary>
    protected void logAllTest()
    {
        bool isDebugEnabled = log.IsDebugEnabled;
        bool isErrorEnabled = log.IsErrorEnabled;
        bool isFatalEnabled = log.IsFatalEnabled;
        bool isInfoEnabled = log.IsInfoEnabled;
        bool isWarnEnabled = log.IsWarnEnabled;
        log.Debug("Debug msg");
        log.Error("Error msg");
        log.Fatal("Fatal msg");
        log.Info("Info msg");
        log.Warn("Warn msg");
    }
}

References: http://www.aspxcode.net/free-asp-net-sample-source-code-c.aspx?Topics=how%20to%20get%20the%20IP%20Address%20of%20the%20Visitor

Sample SQLServer Databases

2009-08-15T22:04:00.000-07:00

2005 and 2008 Sample SQLServer Databases are available here: MSFTDBProdSamples
Northwind and pubs databases are available here: Northwind and pubs

These are useful for testing .NET Data objects by using SQLDatasource as the DataSource.

Highlight Rows in a GridView

2009-08-15T21:13:00.000-07:00

To highlight rows in a GridView you will want to use the GridView DataBound event to add the onmouseover and onmouseout attributes. While CSS methods may work in FireFox browsers, they do not work in Internet Explorer. For the associated javascript method, you can directly set it with this.style.backgroundColor, but this is inflexible. Instead, change the CSS class.

Here is the CSS for the highlighted and normal row (see reference for source of the simple CSS):


<style type="text/css">

.normalRow
{
background-color:white;/* You can update the background Color to normal Gridview Back Color */
cursor:pointer;/* You can change cursor pointer to default, Pointer etc */
}

.highlightRow
{
background-color:Gray;/* You can change the background Color of the row to whatever color you want. You can also give Hexadecimal color code also */
cursor:pointer;/* You can change cursor pointer to default, Pointer etc */
}

</style>

Here is the CodeBehind for the GridView DataBound event:


    protected void GridView1_DataBound(object sender, EventArgs e)
    {
        foreach (GridViewRow row in GridView1.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                row.Attributes.Add("onmouseout", "this.className='normalRow'");
                row.Attributes.Add("onmouseover", "this.className='highlightRow'");
            }
        }
    }

Further modifications for multiple class rows can be made by checking the original CssClass (or checking implicitly by rowCount%currentRow for alternating rows) in the CodeBehind and setting the onmouseout event to switch back to that original class. Another example where this may be necessary is with check box rows that can be selected.

References:

Rid Grid Lines or Borders in a GridView

2009-08-15T20:36:00.000-07:00

Here is how to get rid of Grid lines or borders in a GridView:


<asp:GridView ID="GridView1" GridLines=None  runat="server">
 </asp:GridView>

References: http://forums.asp.net/t/1134618.aspx

What are VB Me and MyBase Equivalents in C#?

2009-08-15T20:17:00.000-07:00

What are VB Me and MyBase Equivalents in C#?

VB	C#
Me	this
MyBase	base

Creating a Pageable Gridview with Customized Pager Buttons

2009-08-15T17:19:00.000-07:00

Matt Berseth put together a great post on creating a pageable GridView. It is basically a custom control that inherits from GridView and implements the DataPageable interface. The coolest part is how the GridView CSS is tailored to a specific looking type of Gridview.

I think it is worth going one step further and tailoring the DataPager with custom images to indicate both enabled and disabled. You will notice that there is a FirstPageImageUrl in the NextPreviousPagerField but no available FirstPage_DisabledImageUrl. To overcome this, we need to examine the DataPager controls dynamically and switch the images according to whether we are already at the start index or last index. This code is placed in the GridView's DataBound event:


        protected void gvProducts_DataBound(object sender, EventArgs e)
        {
            ImageButton ibtn;
            int pgEnd = gvProducts.PageCount;
            int curPg = gvProducts.PageIndex;
            foreach (Control ct in pager.Controls[0].Controls)
            {
                if(ct.GetType().Equals(typeof(ImageButton)))
                {
                    ibtn = ct as ImageButton;
                    if (0 == curPg)
                    {
                        ibtn.ImageUrl = "~/images/PageFirst_Disabled.jpg";
                    }
                    else { ibtn.ImageUrl = "~/images/PageFirst.jpg"; }
                }
            }
            foreach (Control ct in pager.Controls[2].Controls)
            {
                if (ct.GetType().Equals(typeof(ImageButton)))
                {
                    ibtn = ct as ImageButton;
                    if ((pgEnd-1) == curPg)
                    {
                        ibtn.ImageUrl = "~/images/PageLast_Disabled.jpg";
                    }
                    else { ibtn.ImageUrl = "~/images/PageLast.jpg"; }
                }
            }
        }

I also changed the section in Matt's Default.aspx to:


                            <!-- Notice this is outside the GridView -->
                            <div class="pager">
                                <asp:DataPager ID="pager" runat="server" PageSize="8" PagedControlID="gvProducts">
                                    <Fields>
                                        <asp:NextPreviousPagerField
                                            ButtonType="Image"
                                            FirstPageImageUrl="~/images/PageFirst.jpg"                                            
                                            RenderDisabledButtonsAsLabels="false" 
                                            ShowFirstPageButton="true" ShowPreviousPageButton="false" 
                                            ShowLastPageButton="false" ShowNextPageButton="false"
                                        /> 
                                        <asp:NumericPagerField
                                            ButtonCount="7" NumericButtonCssClass="command" 
                                            CurrentPageLabelCssClass="current" NextPreviousButtonCssClass="command"
                                        />
                                        <asp:NextPreviousPagerField 
                                        
                                            ButtonType="Image"
                                            LastPageImageUrl="~/images/PageLast.jpg"
                                            RenderDisabledButtonsAsLabels="false" 
                                            ShowFirstPageButton="false" ShowPreviousPageButton="false" 
                                            ShowLastPageButton="true" ShowNextPageButton="false"
                                        />                                            
                                    </Fields>                            
                                </asp:DataPager>
                            </div>

The crude Microsoft Paint images are located here: http://techron.scottrichmond.com/downloads/2210036646138181629images.zip

Now you know a technique to customize the DataPager. I further customized the buttons to display custom buttons (print, search, etc.) in the center and pager buttons on the right using JavaScript. That involves a lot of screen calculation details and JavaScript that is another topic. Note, the customization comes at a performance cost. This can be improved with direct reference to the control[x].FindControl("myImgControl"), but that requires inspecting how .NET names the ImageButton in the Debugger.

The result is customized ImageButtons for enabled and disabled buttons.

Download/view Matt's code to add in the customization I've written about.

References:

http://mattberseth.com/blog/2008/04/using_a_datapager_with_the_gri.html

http://www.c-sharpcorner.com/UploadFile/nipuntomar/DataPagerGridView08012008123240PM/DataPagerGridView.aspx

Use a Class to Store ConnectionString

2009-08-15T17:08:00.000-07:00

This appears the best way to store database ConnectionString objects in a given Class:


internal static string GetConnectionString(string specifiedConnectionString, bool lookupConnectionString, bool appLevel)
        {
           //Your Conn String goes here!!
           return Factory.ConnectionString;
        }

Notice that a static Class is used since we don't need to waste memory instantiating strings.

References: http://forums.asp.net/p/997608/2209437.aspx
Specifically mentioned was to modify the SQLConnectionHelper.cs from: http://download.microsoft.com/download/a/b/3/ab3c284b-dc9a-473d-b7e3-33bacfcc8e98/ProviderToolkitSamples.msi

Use Column Mapping with MappingType.Hidden to Hide Columns in a DataTable

2009-08-15T17:00:00.000-07:00

It is possible to use Column mapping with MappingType.Hidden to hide columns in a DataTable of a Dataset before the Fill with the following:


myDS.Tables[0].Columns[i].ColumnMapping = MappingType.Hidden;

Of course, 0 may be substituted with the table name as a string. Unfortunately, this is not very useful if the Fill has already created the DataSet. In that case I would probable just want to use an item template in my data display control (such as a GridView) to output the specific fields. The other option is to run the delete columns on the DataTable, which is simply inefficient. Another losing option is to run a select command on the DataTable, which might have its uses for simply acquiring in memory data as opposed to viewing it.

References: http://www.dotnetspider.com/forum/ViewForum.aspx?ForumId=3888

Create a Column in Excel with Leading 0s

2009-08-15T16:50:00.000-07:00

To create a column in Excel with leading 0s given a column A with values 0,1,..., and 12 character string to create, use this formula on the target column:


= RIGHT("000000000000" & A1,12)

The result will be 000000000000,000000000001,...
Then just use the copy, paste special as values technique mentioned earlier.

Reference: http://www.koozie.org/2004/11/excel_leading_z.html

Concatenate two Excel Columns with a Character or String

2009-08-15T16:44:00.000-07:00

To concatenate (or join) two columns A2 and B2 into C2 with a hypen (in this case), use this formula in C2:


=A2&"-"&B2

Then copy the results down the column with click and drag downwards to duplicate the formula on the cell. Finally, copy column C and paste special into the target column as values only.

Reference: http://www.pcmag.com/article2/0,2817,33100,00.asp

How to Create GUID from a String

2009-08-15T16:38:00.000-07:00

This is an easy way, but esoteric task, to create a GUID from a string:


Guid g = new Guid(string);

Reference: http://www.devnewsgroups.net/dotnetframework/t2650-convert-string-guid.aspx

Using Vista to Add a User Account to a Group

2009-08-15T09:50:00.000-07:00

Here is a helpful description of how to add a user account to a group. Of course you probably need Vista Business or Ultimate.

Reference: Using Vista to Add a User Account to a Group

Getting Started With Microsoft Charts

2009-04-14T16:22:00.000-07:00

I just ran across a tutorial on getting started with Microsoft Charts for ASP.NET 3.5. The pre-requisite is to download the chart.exe from http://code.msdn.microsoft.com/mschart Specifically, I clicked the "Chart Controls for .NET Framework" link on that page to download MSChart.exe.

Microsoft offered this in response to Googles Charts by buying Dundee's Charts that was for .NET 2.0. Note, this new one is for 3.5.

SQL Server 2005 database diagram support objects error

2009-03-31T10:37:00.001-07:00

Sql 2005 Database diagram support objects cannot be installed because this database does not have a valid owner...

Solution:
1. Right Click on your database, choose properties
2. Goto the Options Page
3. In the Dropdown at right labeled "Compatibility Level" choose "SQL Server 2005(90)"
4. Goto the Files Page
5. Enter "sa" in the owner textbox.
6. Hit OK

Reference: http://geekswithblogs.net/shahed/archive/2007/11/19/116940.aspx

Incorrect Syntax Near sproc ...

2009-03-19T15:13:00.001-07:00

I got this 'incorrect syntax near spoc (stored procedure)' error from the following:


        string connectionString = getConnectionString("ConnectionString");
        SqlConnection conn = new SqlConnection(connectionString);
        System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand("sproc_aspnet_StocksInLists_RemoveStocksFromList", conn);
        
        try
        {
            conn.Open();
            command.Parameters.AddWithValue("@ListId", ddlList.SelectedValue);
            iRes = command.ExecuteNonQuery();
            if (iRes < 0) throw new Exception("Error removing stocks from list");
        }

The bug fix is to set the command type:


        string connectionString = getConnectionString("ConnectionString");
        SqlConnection conn = new SqlConnection(connectionString);
        System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand("sproc_aspnet_StocksInLists_RemoveStocksFromList", conn);
        command.CommandType = System.Data.CommandType.StoredProcedure;
        try
        {
            conn.Open();
            command.Parameters.AddWithValue("@ListId", ddlList.SelectedValue);
            iRes = command.ExecuteNonQuery();
            if (iRes < 0) throw new Exception("Error removing stocks from list");
        }

Add Google Charts with .NET

2008-12-23T13:54:00.000-08:00

Add Google Charts with .NET.
Go to: http://code.google.com/p/googlechartsharp/
Download DLL.
Save and Unzip to location.

From your project, add reference.
Select DLL.
Copy source code from below:


// using GoogleChartSharp;

        int[] data = new int[] { 40, 30, 20, 10, 0 };

        // Specify chart width and height in pixels
        LineChart chart = new LineChart(150, 150);

        // SetData will accept int[] and float[] for single data sets
        chart.SetData(data);

        string imageUrl = chart.GetUrl();
        Image1.ImageUrl = imageUrl;

Run. Enjoy. Modify. Visit these sites for more:
http://groups.google.com/group/google-chart-api/web/useful-links-to-api-libraries

References:
http://code.google.com/p/googlechartsharp/
http://code.google.com/p/googlechartsharp/wiki/UsageExamples

Get the ApplicationName for Stored Procedure Parameter

2008-12-23T13:51:00.001-08:00

Sometimes the ApplicatonName is necessary for Membership stored procedures. You can access the ApplicationName as follows:


string appName = Membership.ApplicationName;

References: http://msdn.microsoft.com/en-us/library/system.web.security.membership.applicationname(VS.80).aspx

Get the Current Time for Database Storage

2008-12-23T13:46:00.001-08:00

To get the current datetime in UTC format in .net use following:


DateTime dateUTC = DateTime.Now.ToUniversalTime();

You can then store this date in your database.
If you want to display it back to local time use:


DateTime dateLocal = dateUTC.ToLocalTime();

Reference: http://forums.asp.net/t/1217716.aspx

The Difference Between NVARCHAR and VARCHAR

2008-12-23T13:42:00.000-08:00

The main difference between NVARCHAR and VARCHAR is that NVARCHAR extra space allows for easier multi-language support. Therefore, I switched my database's VARCHARs to NVARCHARS.

References: http://july-code.blogspot.com/2008/03/differences-between-varchar-and.html

Accessing ConnectionString from CodeBehind

2008-12-23T13:31:00.000-08:00

Accessing a ConnectionString from CodeBehind requires your connection string to be defined in the web.config file.

Then use this source code:


ConnectionString = System.Configuration.ConfigurationManager.AppSettings["MySetting"].ToString();

I customized my BasePage with a utility function as follows:


    public string getConnectionString(string vConnectionString)
    {
        System.Configuration.Configuration rootWebConfig = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(Request.ApplicationPath);
        System.Configuration.ConnectionStringSettings connString = null;
        string connectionString = string.Empty;
        if (0 < rootWebConfig.ConnectionStrings.ConnectionStrings.Count)
        {
            connString =
                rootWebConfig.ConnectionStrings.ConnectionStrings[vConnectionString];
            if (connString != null)
                connectionString = connString.ConnectionString;
        }
        return connectionString;
    }

References: http://forums.asp.net/p/1353594/2770309.aspx
http://msdn.microsoft.com/en-us/library/ms178411(VS.80).aspx

Use ConnectionString Web.config

2008-12-23T13:20:00.000-08:00

I setup the ConnectionString in my Web.config file and encountered a "'ConnectionStringSettings' is not defined error. The solution was to add the 'system.configuration' library to the project! (Project, Add reference.., then find the library then add it!).

References: http://forums.asp.net/p/1047730/1475561.aspx#1475561

Keeping a DropDownList's DataSource Updated

2008-12-23T13:04:00.000-08:00

The DropDownList does not manage selected state like other controls. Therefore, I use a Session variable to store an index to keep track of the currently selected item:


    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            Session["listId"] = ddlList.SelectedValue;
            GridViewStocksInLists.DataBind();
        }
    }

Now, I add the SelectedIndexChanged event with the following code:


    protected void ddlList_SelectedIndexChanged(object sender, EventArgs e)
    {
        Session["listId"] = ddlList.SelectedValue;
        GridViewStocksInLists.DataBind();
    }

Reference: http://www.velocityreviews.com/forums/t123449-problem-with-formview-and-dropdownlists.html

Use a CustomControl to Set UserId and Use as a DataBindable Property

2008-12-23T12:49:00.001-08:00

Use a CustomControl (named MembershipUser) to Set UserId and Use as a DataBindable Property. Create a MembershipUser CustomControl that has a property named Value that can be DataBound. For example MembershipUser1.Value would fetch the userId:


    [Browsable (true)]
    public string Value
    {
        get
        {
            MembershipUser currentUser;
            currentUser = Membership.GetUser();
            if (currentUser == null)
                return string.Empty;
            return currentUser.ProviderUserKey.ToString();
        }
    }

Reference: This is from http://aspnet.4guysfromrolla.com/articles/110106-1.aspx

Be Careful About uniqueId Parameter in Stored Procedure

2008-12-23T12:40:00.000-08:00

Here is an error I received when my UniqueId parameter in a stored procedure was not valid:


Server Error in '/stockmonger.com' Application.
Conversion failed when converting from a character string to uniqueidentifier.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Conversion failed when converting from a character string to uniqueidentifier.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

I corrected to make sure the parameter was a valid uniqueId paramater and not null.

Modifying DataBound Hyperlinks Text

2008-12-23T12:28:00.000-08:00

Modifying a GridView's Databound Hyperlink text since I couldn't do this easily in the ItemTemplate, I moved the Replace function to the DataBound of the GridView:


    protected void GridViewStocksInLists_DataBound(object sender, EventArgs e)
    {
        int rowId;
        string imgUrl;
        string navUrl;
        for (rowId=0; rowId<GridViewStocksInLists.Rows.Count;rowId++) {
            imgUrl = string.Empty;
            navUrl = string.Empty;
            imgUrl = ((HyperLink)GridViewStocksInLists.Rows[rowId].FindControl("hlChart")).ImageUrl.Replace('$', '^');
            ((HyperLink)GridViewStocksInLists.Rows[rowId].FindControl("hlChart")).ImageUrl = imgUrl;
            navUrl = ((HyperLink)GridViewStocksInLists.Rows[rowId].FindControl("hlChart")).NavigateUrl.Replace('$', '^');
            ((HyperLink)GridViewStocksInLists.Rows[rowId].FindControl("hlChart")).NavigateUrl = navUrl;
        }
    }

This replaced $ with ^ in my HyperLink.

Here is the GridView that contains the HyperLink:


<asp:GridView ID="GridViewStocksInLists" runat="server" DataSourceID="SqlDataSourceGetStocksInList">
                    <RowStyle CssClass="tableAnalysisRow" />
                    <HeaderStyle CssClass="tableAnalysisHeader" />
                    <AlternatingRowStyle CssClass="tableAnalysisAlternatingRow" />
                    <Columns>                  
                        <asp:TemplateField HeaderText="Chart">
                            <ItemTemplate>
                                <asp:HyperLink ID="hlChart" runat="server"
                                ImageUrl='<%# Eval("Symbol", "http://chart.finance.yahoo.com/c/0b/d/{0}").ToLower() %>'
                                NavigateUrl='<%# Eval("Symbol", "http://finance.yahoo.com/q/bc?s={0}&t=1y").ToLower() %>' >
                                </asp:HyperLink>
                            </ItemTemplate>
                        </asp:TemplateField>
                    </Columns>
                </asp:GridView>

References: http://forums.asp.net/p/1263726/2542303.aspx#2542303

Remove HTML Tags

2008-12-23T12:02:00.000-08:00

Remove HTML Tags from a string:


    public static string RemoveHtml(string txt)  
    {  
        return Regex.Replace(txt, @"<[^>]*>", string.Empty);  
    }

Reference: http://www.webpronews.com/expertarticles/2006/12/01/aspnet-remove-html-tags-from-a-string

Using AutoComplete Ajax Control With Separate ID Field from Name Field

2008-12-17T23:00:00.000-08:00

In the previous post, I detailed how to use the SQL stored procedure to select matches.

AutoComplete Extender offers a convenient way to select values froma TextBox. One problem is that multiple details can be displayed, but the whole text is selected by default. I wanted to allow multiple AutoCompletes, select the id without the other details and append the appropriate delimeter in between entries. First, I setup the WebService method. Note that the Stock object has Symbol and Name properties:


   [WebMethod]
    public string[] GetStocksInPrefix(string prefixText, int count)
    {
        int curCount = 0;
        if (count == 0)
        {
            count = 10;
        }
        List<string> items = new List<string>();
        JavaScriptSerializer jss = new JavaScriptSerializer();
        string[] stocks = null;
        string connectionString = getConnectionString("ConnectionString");
        SqlDataReader rdr = null;
        SqlConnection conn = new SqlConnection(connectionString);
        System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand("sproc_aspnet_GetStocksByPrefix", conn);
        try
        {
            command.CommandType = System.Data.CommandType.StoredProcedure;
            conn.Open();
            command.Parameters.AddWithValue("@Prefix", prefixText+"%");
            rdr = command.ExecuteReader();
            string tmp = string.Empty;
            Stock _stock = null;
            while (rdr.Read() && curCount<count )
            {
                _stock = new Stock(rdr["Symbol"].ToString(), rdr["Name"].ToString(), rdr["Exchange"].ToString());
                tmp = rdr["Symbol"] + "\t" + rdr["Name"];
                items.Add(AutoCompleteExtender.CreateAutoCompleteItem(tmp, jss.Serialize(_stock)));
                curCount++;
            }
            command.Parameters.Clear();
        }
        catch (Exception ex)
        {
        }
        finally
        {
            if (rdr != null) rdr.Close();
            if(conn!=null) conn.Close();
        }
        return items.ToArray();
    }

Then, I add the javascript event, 'OnSymbolSelected',to the OnClientItemSelected event in the AutoComplete Extender:


                    <asp:TextBox ID="txtSymbols" runat="server" Width="300px"></asp:TextBox>
                    <cc1:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" 
                        TargetControlID="txtSymbols" ServiceMethod="GetStocksInPrefix" 
                        ServicePath="~/WebServiceAutoCompleteSymbol.asmx" MinimumPrefixLength="2"
                        CompletionListHighlightedItemCssClass="watermark" CompletionSetCount="10"
                        DelimiterCharacters=", "
                        CompletionListElementID="Symbol"
                        CompletionListItemCssClass="watermarkMatch"                        
                        EnableCaching="true" CompletionInterval="1000" OnClientItemSelected="OnSymbolSelected"
                         >
                    </cc1:AutoCompleteExtender>

Finally, add the javascript function to the aspx page. This function reads the Stock object into results, takes the SelectedText and gets the original string before the new text was completed by replacing the completed text with an empty string. If it is an additional field (that does not contain ' ' or ',', then only the id (symbol in this case) is added. Othewise, the original id plus the ' ' delimeter and the new id is added:


<script type="text/javascript" language="javascript">   
    function OnSymbolSelected(source, eventArgs)   
    {   
        var results = eval('('  + eventArgs.get_value() + ')');   
        if (results.symbol != null)   {  
            var symbols = document.getElementById('<%= txtSymbols.ClientID %>').value;
            var original = symbols.replace((results.symbol+'\t'+results.name),'');
            if (original.indexOf(' ')>0 || original.indexOf(',')>0)
                document.getElementById('<%= txtSymbols.ClientID %>').value = original + (' '+ results.symbol);
            else  
                document.getElementById('<%= txtSymbols.ClientID %>').value = results.symbol;
            }
    }   
</script>

References: http://ziqbalbh.wordpress.com/2008/06/11/google-like-autocomplete-suggestions/
http://www.tizag.com/javascriptT/javascript-string-replace.php
http://techron.blogspot.com/2008/04/reading-textbox-or-other-control-values.html

Using LIKE in SQL

2008-12-17T11:07:00.000-08:00

Be careful in the order of parameters while using LIKE in T-SQL. The following stored procedure did not work @Prefix LIKE dbo.aspnet_Stocks.Name. It must be reversed:


set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[sproc_aspnet_GetStocksByPrefix]
    @Prefix as varchar(50)=NULL
AS
BEGIN
            SELECT *
            FROM dbo.aspnet_Stocks
            WHERE ((Symbol LIKE @Prefix) OR ( [Name]LIKE @Prefix))
            RETURN 0    
END

This was used in an AutoComplete AJAX control. The following reference describes the setup.

Reference: http://www.aspdotnetcodes.com/AutoComplete_From_Database.aspx

A more efficient stored procedure would use a FullText Catalog indexed on a Text Column as described here: http://support.microsoft.com/?kbid=916784

Sorting a GridView

2008-12-16T23:37:00.000-08:00

Sorting a GridView with a DataSource requires an external storage variable for a the last SortDirection. First, I call the GridViewReport_Sorting in the Sorting event in the GridView. A GridView has e.SortExpression and e.SortDirection. I combine the two to form a unique Session variable and then set the SortDirection to compare at later sorts:


    protected void GridViewReport_Sorting(object sender, GridViewSortEventArgs e)
    {
        DataTable dt;
        DataView dv;
        dt = (DataTable)Cache["dvStocks"];
        dv = new DataView(dt);
        string direction = SortDirection.Descending.ToString();
        string curDirecton = SortDirection.Ascending.ToString(); // set to default
        string key = string.Concat(e.SortExpression, e.SortDirection);
        if(Session[key]!=null) {
            curDirecton = (string)Session[key];
        }
        if (curDirecton.Contains("Ascending"))
        {
            direction = Global.DESC; //DESC
            Session[key] = SortDirection.Descending.ToString();
        }
        else
        {
            direction = Global.ASC; //ASC
            Session[key] = SortDirection.Ascending.ToString();
        }
        dv.Sort = e.SortExpression + " " + direction;
        Cache["dtCalculated"] = dv.ToTable();
        GridViewReport.DataSource = dv;
        GridViewReport.DataBind();
    }

Reference: http://forums.asp.net/t/825118.aspx

Using static strings and objects to increase performance and maintainence

2008-12-15T15:42:00.000-08:00

I found this global variable article below to help me with using static strings and objects to increase performance and maintainence.

For example, suppose I have an error message, "Error: ", that I might want to change to "There was a problem: ". Instead of search and replace n times, I could just use a static string variable to change the string value.

Sample Global class:


/// <summary>
/// Summary description for Global
/// </summary>
public static class Global
{
    public static string CSS_HIDDEN
    {
        get { return "hidden"; }
    }
    public static string CSS_EMPTY
    {
        get { return string.Empty; }
    }
    public static string CSS_CONTENT
    {
        get { return "content1"; }
    }
    public static string ERROR_HEADER_HTML
    {
        get { return "<red>There was a problem:</red></br>"; }
    }
    public static string ERROR_HEADER
    {
        get { return "There was a problem:"; }
    }
}

Then one just accesses it with Global.ERROR_HEADER. Notice that there is no declarative instantiation for the static class.

Reference: http://dotnetperls.com/Content/Global-Variables-ASPNET.aspx

Use securitytrimming to limit role views of Menu and SiteMap

2008-12-14T14:37:00.000-08:00

Use securitytrimming to limit role views of Menu and SiteMap.

Modify the Web.config file's configuration tag with:


    <system.web>
    <siteMap defaultProvider="secureProvider">
      <providers>
        <add name="secureProvider" type="System.Web.Xml




Provider"
             siteMapFile="web.sitemap" securityTrimmingEnabled="true"/>
      </providers>
    </siteMap>
    </system.web>

Then modify Web.sitemap to make sure roles parameter is set to * or admin. Notice how I explicitly set the nodes roles parameter in the links outside the website


<?xml version="1.0" encoding="utf-8" ?>
<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" >
  <siteMapNode url="SiteMap.aspx" title="Site Map"  description="Site Map">
    <siteMapNode url="Default.aspx" title="Home"  description="Home" roles="*">
      <siteMapNode url="Login.aspx" title="Login/Logout"  description="Login or Logout" />
      <siteMapNode url="About.aspx" title="About"  description="About" />
    </siteMapNode>
    <siteMapNode url="~/Tools/Tools.aspx" title="Tools"  description="" roles="*">
      <siteMapNode url="~/Tools/GrowthAnalysis.aspx" title="Growth Analysis"  description="" />
      <siteMapNode url="~/Tools/FundamentalAnalysis.aspx" title="Fundamental Analysis"  description="" />
      <siteMapNode url="~/Tools/PriceToSalesAnalysis.aspx" title="Price To Sales Analysis"  description="" />
      <siteMapNode url="~/Tools/TechnicalAnalysis.aspx" title="Technical Analysis"  description="" />
    </siteMapNode>
    <siteMapNode url="~/MyLists/MyLists.aspx" title="My Lists"  description="" roles="*">
      <siteMapNode url="~/MyLists/Management.aspx" title="Management"  description="" />
      <siteMapNode url="~/MyLists/Tracker.aspx" title="Tracker"  description="" />
    </siteMapNode>
    <siteMapNode url="~/MarketWatch/MarketWatch.aspx" title="Market Watch"  description="" roles="*">
      <siteMapNode url="~/MarketWatch/MarketSummary.aspx" title="Market Summary"  description="" />
      <siteMapNode url="~/MarketWatch/SectorSummary.aspx" title="Sector Summary"  description="" />
      <siteMapNode url="~/MarketWatch/IntermarketSummary.aspx" title="Inter-market Summary"  description="" />
      <siteMapNode url="~/MarketWatch/WorldMarketSummary.aspx" title="World Market Summary"  description="" />
    </siteMapNode>
    <siteMapNode url="~/Media.aspx" title="Media" description="" roles="*">
      <siteMapNode url="http://www.bloomberg.com/news/av/" title="Bloomberg Audio/Video" description="" roles="*" />
      <siteMapNode url="http://www.thestreet.com/_tscnav/audio/taskaudio/index.html" title="Real Story With Aaron Task"  description="" roles="*" />
      <siteMapNode url="http://www.thestreet.com/_tscnav/video/index.html" title="TheStreet.com TV" description="" roles="*" />
      <siteMapNode url="http://online.wsj.com/public/us" title="Wall Street Journal"  description="" roles="*" />
      <siteMapNode url="http://www.nytimes.com/pages/business/index.html" title="New York Times Business"  description="" roles="*" />
      <siteMapNode url="http://markets.usatoday.com/custom/usatoday-com/html-markets.asp" title="USA Today Markets" description="" roles="*" />
      <siteMapNode url="http://www.briefing.com/Investor/Public/MarketSnapshot/HeadlineHits.htm" title="Briefing.com Headline Hits" description="" roles="*" />
      <siteMapNode url="http://www.pbs.org/nbr/" title="PBS Nightly Business Report" description="" roles="*" />
      <siteMapNode url="http://www.redoption.com/shadow_video.php" title="RedOption Shadow Trader Video" description="Weekend Update" roles="*" />
    </siteMapNode>
    <siteMapNode url="~/Commentary.aspx" title="Commentary"  description="" roles="*">
      <siteMapNode url="http://stockmonger.blogspot.com/" title="Stock Monger"  description="" roles="*" />
      <siteMapNode url="http://find.thestreet.com/cgi-bin/texis/find/results.html?nh=20&amp;t=Cramer" title="Jim Cramer"  description="" roles="*" />
      <siteMapNode url="http://www.rightsideadvisors.com/advisors/default.aspx?" title="Richard Suttmeier"  description="" roles="*" />
      <siteMapNode url="http://articles.moneycentral.msn.com/Commentary/Experts/Jubak/Jim_Jubak.aspx" title="Jim Jubak"  description="" roles="*" />
      <siteMapNode url="http://bigpicture.typepad.com/" title="The Big Picture With Barry Ritholtz"  description="" roles="*" />
    </siteMapNode>
    <siteMapNode url="~/Admin/Admin.aspx" title="Admin" description="" roles="Admin">
      <siteMapNode url="~/Admin/UpdateAllStocks.aspx" title="Update All Stocks" description="" roles="Admin"  />
      <siteMapNode url="~/Admin/StockScaffold.aspx" title="Stock Scaffold"  description="" roles="Admin" />
      <siteMapNode url="~/Admin/ManageRoles.aspx" title="Manager User Roles"  description="" roles="Admin" />
      <siteMapNode url="~/Admin/ManageLists.aspx" title="Manage Lists"  description="" roles="Admin" />
    </siteMapNode>
  </siteMapNode>
</siteMap>

Beginning Subversion (SVN) for .NET

2008-07-25T14:55:00.000-07:00

I've had enough of zipping my project for backup before editing it. I mean it works fine for personal development, but for team projects it is time for a versioning system. That means either using CVS (Control Versioning System) or SVN (Subversion), since VSS (Visual Source Safe) would be too expensive.

First you need the download and install subversion: http://subversion.tigris.org/

Next you need to create the repository. Suppose you've created your svn directory. Fire up the command prompt and navigate there. create the "MyProject" repository:
svnadmin create MyProject

Next, recognize the recommended standard structures:
svn/MyProject
svn/MyProject/trunk
svn/MyProject/branches
svn/MyProject/tags

Next, place the trunk directory in hte MyProject directory and the .NET actual Website directory in the trunk:
svn/MyProject/trunk/MyWebsite

Next, checkout the project:
svn checkout "file:///c:/documents and settings/user/svn/MyProject"

Next, add the trunk, branches, and tags folders to the MyProject repository:
cd MyProject
svn mkdir trunk
svn mkdir branches
svn update
svn add tags

Next, commit the updates to in effect check-in the project:
svn commit -m "initial project setup"

References:
http://www.germane-software.com/~ser/R_n_R/subversion.html
http://www.onlamp.com/pub/a/bsd/2005/08/11/FreeBSD_Basics.html?page=2
http://svnbook.red-bean.com/

Opposite Conventions List

2008-07-19T13:45:00.000-07:00

Here is a list of opposing actions to help maintain consistent conventions:
add/remove
increment/decrement
open/close
begin/end
insert/delete
show/hide
create/destroy
lock/unlock
source/target
first/last
min/max
start/stop
get/put
next/previous
up/down
get/set
old/new
Reference: Code Complete

Wiki Trials and Errors

2008-07-12T16:16:00.000-07:00

I read about Wikis in Code Complete and decided to try some out for software design. This was my first contact beyond the famous Wikipedia. Wikis are basically editable html pages for documenting facts, design, and collaborating amongst users. Here are the results:

I tried FlexWiki and read their basic documentation to add namespaces and edit pages. I set it up on my localhost and continuously ran into 404 errors after updating a page. The few fixes I read about looked incomplete, so I scrapped the FlexWiki.

Next I installed DokuWiki from a PHP application on my Kensoft server. I'll update the review when I'm done setting up a sample. But in the meantime, I'd recommend avoiding FlexWiki.

Reference: http://www.splitbrain.org/go/dokuwiki

Using a GridView with Edit and Delete that use stored procedures

2008-07-03T01:51:00.000-07:00

Here is how to use a GridView with Edit and Delete that use stored procedures for update and delete. First, the aspx:


        <asp:GridView ID="gvEmail" runat="server" AutoGenerateDeleteButton="True" 
        AutoGenerateEditButton="True" AutoGenerateColumns="False" DataSourceID="SqlDataSource1"
        AllowPaging="True" OnRowDeleting="gvEmail_RowDeleting" PageSize="99" OnRowUpdating="gvEmail_OnRowUpdating">
            <Columns>
                <asp:BoundField DataField="email" HeaderText="email" SortExpression="email" />
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
            SelectCommand="SELECT [email] FROM [vw_Email]"
            DeleteCommand="sproc_DeleteEmail" DeleteCommandType="StoredProcedure"
            UpdateCommand="sproc_UpdateEmail" UpdateCommandType="StoredProcedure"
            >
            <DeleteParameters><asp:Parameter Name="email" Type="String" /></DeleteParameters>
            <UpdateParameters>
                <asp:Parameter Name="email" Type="String" />
                <asp:Parameter Name="newEmail" Type="String" />
            </UpdateParameters>
            </asp:SqlDataSource>

Now the code behind.


    protected void gvEmail_RowDeleting(object sender, GridViewDeleteEventArgs e) //DELETE
    {
        SqlConnection conn = new SqlConnection(SqlDataSource1.ConnectionString);
        System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand("sproc_DeleteEmail", conn);
        command.CommandType = System.Data.CommandType.StoredProcedure;
        conn.Open();
        string email = string.Empty;
        DataControlFieldCell cell = gvEmail.Rows[e.RowIndex].Cells[1] as DataControlFieldCell;
        gvEmail.Columns[0].ExtractValuesFromCell(
            e.Keys,
            cell,
            DataControlRowState.Normal,
            true);
        email = e.Keys[0].ToString();
        if (!string.IsNullOrEmpty(email))
        {
            command.Parameters.AddWithValue("@email", email);
            command.ExecuteNonQuery();
        }
        command.Parameters.Clear();
        conn.Close();
    }
    protected void gvEmail_OnRowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        SqlConnection conn = new SqlConnection(SqlDataSource1.ConnectionString);
        System.Data.SqlClient.SqlCommand command = new System.Data.SqlClient.SqlCommand("sproc_UpdateEmail", conn);
        command.CommandType = System.Data.CommandType.StoredProcedure;
        conn.Open();
        string newEmail = e.NewValues[0] as string;
        string email = e.OldValues[0] as string;
        if (!string.IsNullOrEmpty(email))
        {
            command.Parameters.AddWithValue("@email", email);
            command.Parameters.AddWithValue("@newEmail", newEmail);
            command.ExecuteNonQuery();
        }
        command.Parameters.Clear();
        conn.Close();
    }

Note: Exception handling left off for brevity.
Reference: http://www.developerfusion.co.uk/show/91/7/

Using XML and XPath for a GridView

2008-07-01T15:43:00.000-07:00

This demonstrates how to use XML and XPath with a GridView to display links:


    <asp:GridView ID="gvLinks" runat="server" DataSourceID="XmlDataSource1" AutoGenerateColumns="False">
    <Columns>
        <asp:TemplateField HeaderText="Link">
            <ItemTemplate>    
            <asp:HyperLink ID="HyperLink1" runat="server" Target="_blank" NavigateUrl='<%#XPath("href") %>'>
                <%#XPath("title")%>
            </asp:HyperLink>
            </ItemTemplate>    
        </asp:TemplateField>
        <asp:TemplateField HeaderText="Description">
            <ItemTemplate>
                <asp:Label ID="lblrOwner" runat="server" Text=&lt;%#XPath("description")%&gt;></asp:Label>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
    </asp:GridView>
    <asp:XmlDataSource ID="XmlDataSource1" runat="server" DataFile="~/App_Data/Links.xml"
        XPath="links/link"></asp:XmlDataSource>

Here is the XML file:


<?xml version="1.0" encoding="utf-8" ?>
<links>
  <link>
    <title>Yahoo</title>
    <href>http://www.yahoo.com/</href>
    <owner>Yang</owner>
    <description>Yahoo web portal</description>
  </link>
  <link>
    <title>MSN</title>
    <href>http://www.msn.com/</href>
    <owner>Balmer</owner>
    <description>Microsoft web portal</description>
  </link>
  <link>
    <title>Delicious</title>
    <href>http://del.icio.us/</href>
    <owner></owner>
    <description>Internet bookmark manager</description>
  </link>
  <link>
    <title>YouTube</title>
    <href>http://youtube.com/</href>
    <owner></owner>
    <description>Internet videos</description>
  </link>
  <link>
    <title>SlashDot</title>
    <href>http://slashdot.org/</href>
    <owner></owner>
    <description>News that matters</description>
  </link>  
  
</links>

Reference: http://bytes.com/forum/thread528704.html

Opening, Reading, and Writing a file

2008-06-23T16:33:00.000-07:00

Here is an example of Opening/Reading a file in btnOpen_Click and Writing in btnSave_Click:


    protected void btnOpen_Click(object sender, EventArgs e)
    {
        if (string.IsNullOrEmpty(txtFileName.Text)) txtFileName.Text="c:/temp/temp.txt";
        StreamReader sr = null;
        try
        {
            sr = new StreamReader(txtFileName.Text);
            txtFileContent.Text = sr.ReadToEnd();
            sr.Close();
            displayMessage("Successfully opened file");
        }
        catch (Exception ex)
        {
            displayMessage(ex.Message);
        }
        finally
        {
            sr.Close();
        }
    }
    protected void btnSave_Click(object sender, EventArgs e)
    {
        if (string.IsNullOrEmpty(txtFileName.Text)) txtFileName.Text = "c:/temp/temp.txt";
        StreamWriter sw = null;
        try{
            sw = new StreamWriter(txtFileName.Text);
            string[] ar;
            ar = txtFileContent.Text.Split(Environment.NewLine.ToCharArray());
            foreach (string sIn in ar)
            {
                if(!string.IsNullOrEmpty(sIn))
                    sw.Write(sIn.Trim()+Environment.NewLine);
            }
        }catch (Exception ex) 
        {
            displayMessageLine(ex.Message);
        }
        finally{
            sw.Close();
        }
    }

Using a nullable boolean.

2008-06-21T15:16:00.000-07:00

It is possible to assign a nullable boolean in C#. The trick is to use ? in the declaration. Once declared, one can use the HasValue() method. An example follows:


    protected void Page_Load(object sender, EventArgs e)
    {
        bool? isUser = null;
        lblStatus.Text = isUser.HasValue.ToString(); //displays false
        // an int example: Nullable<int> i = null;
    }
    protected void btnCheckStatus_Click(object sender, EventArgs e)
    {
        bool? isUser = false;
        lblStatus.Text = isUser.HasValue.ToString(); //displays true
    }

Clearing controls in GridView row using delete

2008-06-05T10:22:00.000-07:00

Here is how to clear controls in GridView row using delete. Be careful that GridViewDeleteEventArgs is not GridViewDeletedEventArgs!


                                <asp:GridView ID="gvStolenStatusInfo" runat="server" AutoGenerateColumns="false" AllowPaging="true"
                                    EmptyDataText="No records found." PageSize="10" CssClass="gridView"
                                    OnRowDeleting="gvStolenStatusInfo_RowDeleting" AutoGenerateDeleteButton="true">
                                    <Columns>
                                        <asp:TemplateField HeaderText="Status">
                                            <ItemTemplate>
                                                <asp:TextBox ID="txtuCode" runat="server" Text='<%# Bind("Code") %>' />
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField HeaderText="Comment">
                                            <ItemTemplate>
                                                <asp:TextBox ID="txtuComment" runat="server" Text='<%# Bind("Comment") %>' />
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                    </Columns>
                                </asp:GridView>

Notice the OnRowDeleting set to x_RowDeleting function and AutoGenerateDeleteButton. Now for the delete function:


    protected void gvStolenStatusInfo_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        int rowID = e.RowIndex;
        ((TextBox)gvStolenStatusInfo.Rows[rowID].FindControl("txtuCode")).Text = string.Empty;
        ((TextBox)gvStolenStatusInfo.Rows[rowID].FindControl("txtuDate")).Text = string.Empty;
    }

References: http://www.codeproject.com/KB/webforms/Editable_GridView.aspx

Multiple PostBack problem with GridView

2008-05-05T14:41:00.001-07:00

I noticed my SelectedIndexChanged method being called twice in IE7 when I selected a gridview row. I used solution 2 at http://www.codeproject.com/KB/aspnet/GVImageCommandButtonProb.aspx to solve the problem.

Resetting a StringBuilder

2008-05-05T13:09:00.001-07:00

Here is how to reset a StringBuilder:


myStringBuilder.Length = 0;

myStringBuilder.Remove(0, myStringBuilder.Length) also works, but why bother with that one?
References: http://forums.asp.net/t/1193708.aspx

Creating a GUID from scatch

2008-04-25T10:58:00.000-07:00

Sometimes you might want a psuedo-random string value. This can be done with:
System.Guid.NewGuid().ToString();

Changing the default login page for use with LoginStatus control

2008-04-05T15:15:00.000-07:00

Sometimes it is desirable to have a different default login page. For example, a simple site where administrators login at http://foo.com/admin/Login.aspx versus the standard http:foo.com/Login.aspx. The LoginStatus control will hyperlink back to the default login page. To change this default login page, change the web.config file as follows:


    <authentication mode="Forms" >
      <forms loginUrl="~/admin/Login.aspx"></forms>
    </authentication>

Reference: http://erlend.oftedal.no/blog/?blogid=55

How to trim a string in javascript

2008-04-02T17:17:00.000-07:00

How to trim a string in javascript:


var trimmed = str.replace(/^\s+|\s+$/g, '') ;

Reference: http://www.nicknettleton.com/zine/javascript/trim-a-string-in-javascript

Reading TextBox or other Control values with javascript

2008-04-02T13:00:00.000-07:00

Reading TextBox or other Control values with javascript.
Assume TextBox ID="txtName"
First, there are the simple examples of a standard aspx page:


<script type="text/javascript" languague="javascript">
   function simple1() {
      var txtVal = $get('<%= txtName.ClientID %>').value;
   }
   function simple2() {
      var txtVal = $document.getElementById('<%= txtName.ClientID %>').value;
   }
</script>

Here is the complex sample used for accessing a MasterPage's updatePanel for example:


// In the ASPX class
private string scriptKey = "alertName";
private string script = "function alertName() { var txt = document.getElementById('[txtNameID]'); alert(txt.value); }"; 

// In the Page_Load event
script = script.Replace("[txtNameID]", txtName.ClientID);
ClientScript.RegisterClientScriptBlock(this.Page.GetType(), scriptKey, script, true);

references: http://www.velocityreviews.com/forums/t109803-callback-manager-masterpage.html

const and static declarations

2008-03-28T14:46:00.000-07:00

const and static declarations cannot be declared together because they are always together when marked const.
Reference: http://blogs.msdn.com/csharpfaq/archive/2004/03/12/88416.aspx

Simulating a time spanned event with the sleep event

2008-03-27T10:54:00.000-07:00

Here is how to simulate a time spanned event with the sleep event and a millisecond argument:


System.Threading.Thread.Sleep(2000);

Configure SQL Database for User Login

2008-03-27T08:40:00.000-07:00

If you try and set up User Login without configuring the web.config file and try to login from a hosted site you might get an error similar to :" An attempt to attach an auto-named database for file C:\Documents and Settings\Administrator\My Documents\Visual Studio 2005\WebSites\WebSite1\App_Data\aspnetdb.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share. "
To configure it for User Login, I first added the user database to the SQL server using this method.

Next, I changed the web.config file to include:


  <connectionStrings>
    <add name="ConnectionString" connectionString="Data Source=my.host.net;Database=myDatabase;uid=myUserId;pwd=myPassword" providerName="System.Data.SqlClient"/>
  </connectionStrings>
    <system.web>
        <authentication mode="Forms" />
    
    <membership defaultProvider="AspNetSqlMembershipProvider">
      <providers>
        <clear/>
        <add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider, System.Web, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" connectionStringName="LocalSqlServersm" requiresQuestionAndAnswer="true" requiresUniqueEmail="true" passwordFormat="Hashed" minRequiredNonalphanumericCharacters="0" minRequiredPasswordLength="3" applicationName="/" enablePasswordRetrieval="false" enablePasswordReset="true" maxInvalidPasswordAttempts="3"/>
      </providers>
    </membership>
    
  <roleManager enabled="true" />

Just change the myX fields to your fields. And now your configuration manager should work to add users and roles.

Running a client-side application using javascript in asp.net

2008-03-24T11:42:00.000-07:00

Here is how to run a client-side application (.exe) using javascript in asp.net. I don't recommend it, because you probably have to lower your IE security (Tools -> Internet Options -> Security... and allow unsafe activeX).


    <script language="javascript" type="text/javascript">
        function btnSubmit_Click() {
            var WshShell = new ActiveXObject("WScript.Shell"); 
            WshShell.Run("calc.exe"); 
        }
    </script>
    <div>
        <asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClientClick="btnSubmit_Click();" />
    </div>

reference: http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/Q_11275014.html

Setting focus in a user control

2008-03-20T21:44:00.000-07:00

Here is how to set focus in a user control. I used it in an update panel.

ScriptManager.GetCurrent(this.Page).SetFocus(txtTarget);

Giving Stored Procedure Permissions

2008-03-15T01:15:00.000-07:00

To give the required permissions in SQL Server Management Express SQL 2005 database, go to Security -> Schemas. Select the target schema. Right click for properties and Add the target user to the Execute Permission.

Prevent wrapping in table cell

2008-03-04T20:02:00.001-08:00

Prevent wrapping in table cell. Since the old nowrap method is out of favor, the new method is to use:


<td style="white-space:nowrap"> foo </td>

reference: http://www.thescripts.com/forum/thread468471.html
Note: this also works with a Calendar Extender and TextBox even if the cell is too short.

Previewing a TextBox that has HTML with a Popup Window

2008-03-02T22:42:00.000-08:00

Here is a nifty way to preview HTML in a TextBox. I use the ScriptManager and $get the TextBox ID before popping the window and then filling it.


        <script type="text/javascript" language="javascript" >
        function preview() {
            var txt= $get('txtContent');
            var sHTML= txt.value;
            win = window.open(", ", 'popup', 'toolbar = no, status = no');
            win.document.write("" + sHTML + "");
        }
        </script>

Reference: http://javascript.internet.com/forms/html-preview.html

SQL Server Management Studio Express Review

2008-03-02T21:39:00.000-08:00

SQL Server Management Studio Express is fine GUI for manipulating your database. Unfortunately, the problems I've been having are due to the complete lack of robustness. Try copying over 500 records to your table via the cut and paste Excel method and you should expect the program to freeze up and maybe have success. I would recommend using your own stored procedure (SPROC) for data uploading tasks. It is more cumbersome, but at least it works for large data handling.

Unable to cast object of type Foo to object of type Foo

2008-03-02T19:49:00.000-08:00

I would get the error: Unable to cast object of type Foo to object of type Foo in my dynamic control. I read some problems about that kind of error and it said to make sure the Control was set to null before the cast. No error afterwards, at least so far.

Setting up form for HTML Email and Avoiding HttpRequestValidationException

2008-03-02T17:46:00.000-08:00

In a previous post I showed you how to set up .NET for email. But what if I want to send it as HTML. I tried and received this error: System.Web.HttpRequestValidationException: A potentially dangerous Request.Form value was detected from the client ...

The validation problem is solved by setting the Page attribute Validation="false". But then when I sent the HTML it was received as text.

The solution is to use IsHTML=true In my example, I used a check box:


    protected void btnSend_Click(object sender, EventArgs e)
    {
        string sTo = "jane@foo.com";
        string sFrom = ddlFrom.SelectedItem.Text.Trim();
        string sSubject = txtSubject.Text.Trim();
        string sBody = txtContent.Text.Trim();
        lblStatus.Text = "Sending... please wait";
        MailMessage msg = new MailMessage(sFrom, sTo, sSubject, sBody);
        msg.IsBodyHtml = chkIsHTML.Checked;
        SmtpClient mailObj = new SmtpClient("localHost");
        mailObj.Credentials = new NetworkCredential("username", "password");
        mailObj.Send(msg);
        clearTexts();
        lblStatus.Text = "Success: Sent message to Jane at " + DateTime.Now.ToLongTimeString() + " Eastern.";
    
    }

References: http://www.hintsandtips.com/ShowPost/131/hat.aspx
http://aspnet.4guysfromrolla.com/articles/080206-1.aspx

Lazy Load Panel Courtesy of TabContainer and UpdatePanel

2008-02-27T23:58:00.000-08:00

Here is how I implemented a Lazy load Panel. This is a nifty way to have a mini-menu of tabs without some big data transfer happening all at once. The ASP.NET render after complete model makes incremental rendering a necessary task of the developer or else the users will take a hike. This is my adaptation of Matt Burseth's example that should be helpful to avoid the LESSTHAN%= and LESSTHAN%# problems that I had. Remember to put the js in the form tag (probably below the ScriptManager). Two parts below are the ASPX and Code Behind. ASPX:


<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Lazy Load Panel Page</title>
   
</head>
<body>
    <form id="form1" runat="server">
        <ajax:ScriptManager ID="ScriptManager1" runat="server">
        </ajax:ScriptManager>
    <script type="text/javascript" language="javascript"> 
    //var _updateProgressDiv;
    
    function pageLoad(sender, args) {
        // register for our eveents
        Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
        Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequest);
        
        //_updateProgressDiv = $get('ActionProgress');
    }
    function beginRequest(sender, args) {
        // get the gridview element
        var tabContainer = $get('<%= this.tcTest.ClientID %>');
        alert(tabContainer);
        // make it visible
       // _updateProgressDiv.style.display='';       
    }
    function endRequest(sender, args) {
        // make it invisible
       // _updateProgressDiv.style.display='none';
    }
            
        function clientActiveTabChanged(sender, args) {
            // see if table elements for the grids exist yet
            var isTab1Loaded = $get('<%= this.gv1.ClientID %>');
            var isTab2Loaded = $get('<%= this.gv2.ClientID %>');
            var isTab3Loaded = $get('<%= this.gv3.ClientID %>');
            
            // if tab does not exist and it is the active tab, trigger the async-postback
             alert(isTab1Loaded + ',' + isTab2Loaded + ',' + isTab3Loaded + ':' + sender.get_activeTabIndex());
            if (!isTab1Loaded && sender.get_activeTabIndex() == 0) {
                // load tab1
               // alert('fire1');
                __doPostBack('<%= btn1Trigger.UniqueID %>', '');
            }
            if (!isTab2Loaded && sender.get_activeTabIndex() == 1 ) {
                // load tab2
              //  alert('fire2');
                __doPostBack('<%= btn2Trigger.UniqueID %>', '');
            }
            if (!isTab3Loaded && sender.get_activeTabIndex() == 2 ) {
                // load tab3
               // alert('fire3');
                __doPostBack('<%= btn3Trigger.UniqueID %>', '');
            }
        }
    </script>         
        <input id="btn1Trigger" runat="server" type="button" style="display:none" onserverclick="btn1Trigger_Click" />
        <input id="btn2Trigger" runat="server" type="button" style="display:none" onserverclick="btn2Trigger_Click" />
        <input id="btn3Trigger" runat="server" type="button" style="display:none" onserverclick="btn3Trigger_Click" />
        
    <div>
        <ajaxc:TabContainer ID="tcTest" runat="server" OnClientActiveTabChanged="clientActiveTabChanged" ActiveTabIndex="0">
            <ajaxc:TabPanel ID="tp1" runat="server" HeaderText="TabPanel1">
                <ContentTemplate>
                    <ajax:UpdatePanel ID="upnl1" runat="server" UpdateMode="Conditional">
                        <ContentTemplate>
                        1<br />
                            <asp:GridView ID="gv1" runat="server" Visible="true" DataSourceID="sqlLicStatus">
                            </asp:GridView>
                        </ContentTemplate>
                        <Triggers>
                            <ajax:AsyncPostBackTrigger ControlID="btn1Trigger" />
                        </Triggers>
                    </ajax:UpdatePanel>
                </ContentTemplate>
            </ajaxc:TabPanel>
            
            <ajaxc:TabPanel ID="tp2" runat="server" HeaderText="TabPanel2">
                <ContentTemplate>
                    <ajax:UpdatePanel ID="upnl2" runat="server" UpdateMode="Conditional">
                        <ContentTemplate>
                        2<br />
                            <asp:GridView ID="gv2" runat="server" Visible="False" DataSourceID="sqlCondition" >
                            </asp:GridView>
                        </ContentTemplate>
                        <Triggers>
                            <ajax:AsyncPostBackTrigger ControlID="btn2Trigger" />
                        </Triggers>
                    </ajax:UpdatePanel>
                </ContentTemplate>
            </ajaxc:TabPanel>
            
            <ajaxc:TabPanel ID="tp3" runat="server" HeaderText="TabPanel3">
                <ContentTemplate>
                    <ajax:UpdatePanel ID="upnl3" runat="server" UpdateMode="Conditional">
                        <ContentTemplate>
                        3<br />
                            <asp:GridView ID="gv3" runat="server" Visible="False" DataSourceID="sqlCondition" >
                            </asp:GridView>
                        </ContentTemplate>
                        <Triggers>
                            <ajax:AsyncPostBackTrigger ControlID="btn3Trigger" />
                        </Triggers>
                    </ajax:UpdatePanel>
                </ContentTemplate>
            </ajaxc:TabPanel>
            
        </ajaxc:TabContainer>    
    </div>
    
    
    
    
    
            <asp:SqlDataSource ID="sqlLicStatus" runat="server" 
            ProviderName="System.Data.Bar"
            DataSourceMode="DataReader" 
            ConnectionString="foo" 
            SelectCommand="SELECT foo FROM Validations WHERE bar=102 ORDER BY Code;">
        </asp:SqlDataSource>
        <asp:SqlDataSource ID="sqlCondition" runat="server" 
            ProviderName="System.Data.Foo"
            DataSourceMode="DataReader" 
            ConnectionString="foo" 
            SelectCommand="SELECT foo FROM Validations WHERE bar=18 ORDER BY Code;">
        </asp:SqlDataSource>
    </form>
</body>
</html>

Code Behind:


/// <summary>
/// Lazy load TabPanel in a TabContainer
/// The update panel contents are fetched if client trigger is fired.
/// The client trigger is fired if the target tab is active and the 
/// target GridView is not active (visible).
/// </summary>
public partial class Samples_LazyPanel : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void btn1Trigger_Click(object sender, EventArgs args)
    {
        this.gv1.Visible = true;
        this.gv1.DataBind();
    }
    protected void btn2Trigger_Click(object sender, EventArgs args)
    {
        this.gv2.Visible = true;
        this.gv2.DataBind();
    }
    protected void btn3Trigger_Click(object sender, EventArgs args)
    {
        this.gv3.Visible = true;
        this.gv3.DataBind();
    }
}

Simple and Complex Drilldown for ASP.Net Objects

2008-02-27T16:25:00.000-08:00

It can be difficult to drill down through an ASPX page to see where your desired object is before you call FindControl. One quick way to figure out the control tree structure is the Document Outline tab of Microsoft Visual Studio. The only caveat is that you will still need to know your Master Page structure.

The complex overkill way is to use Trace="true" under the Page Directive (at the top of the aspx page.) This has other applications as well. For example, instead of debug prints you can see the state of many variables.

Web User Control Library error

2008-02-27T00:18:00.000-08:00

When you create a User Control from a class and try to drag and drop the control into the design page, you may get an Invalid FORMATETC structure (Exception from HRESULT: 0x80040064 (DV_E_FORMATETC)) error. Talk about confusing. My solution was to make my (user control) class public.

Prevent RadioButtonList from forcing a line break

2008-02-21T11:46:00.000-08:00

Prevent RadioButtonList from forcing a line break by placing the control in a span and set the RepeatLayout attribute to Flow.

Reference: http://www.webdeveloper.com/forum/showthread.php?t=138562

Using Web.config hash for variables using add, key, and value

2008-02-19T18:13:00.000-08:00

Use configuration (web.config) hash to set variables. First, there is the web.config file section: ...


<configuration>
   <appSettings>
      <add key="fooLink" value="http://www.foo.htm"/> 
   </appSettings>
</configuration>

Now in the code-behind I can set a Hyperlink variable as follows:


HyperLinkFoo.NavigateUrl = ConfigurationManager.AppSettings["fooLink"].ToString().ToLower();

Drilling down a nested master page in ASP.NET to reset a form

2008-02-18T20:26:00.000-08:00

Here is an example of drilling down a master page in ASP.NET to reset a form's TextBox controls:


    protected void btnqReset_Click(object sender, EventArgs e)
    {

        try
        {
            ContentPlaceHolder childMasterContent = (ContentPlaceHolder)Page.Form.FindControl("ParentMasterContent").FindControl("ChildMasterContent");
            Control ctrlForm = childMasterContent.FindControl("upnlQueryMoreCriteria").FindControl("pnlQueryMoreCriteria");
            Control[] queryControls = { ctrlForm };
            for (int i = 0; i < 1; i++)
            {
                if (queryControls[i].Controls != null)
                {
                    foreach (Control ct in queryControls[i].Controls)
                    {
                        if (ct.GetType().ToString().Equals("System.Web.UI.WebControls.TextBox"))
                        {
                            ((TextBox)ct).Text = "";
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            log.Error("Unable to reset query criteria: " + ex.Message + ex.StackTrace);
            
        }
    }

Intercepting return in list menu items in ASP.NET

2008-02-18T20:13:00.000-08:00

Here is how I was able to intercept the return button in my list menu item when selected, despite a default button on the aspx page:


<li><a href="" onkeydown="if (event.keyCode==13)  { window.location.href='http://www.foo.com';}"</a></li>

FindContol Solution to add Javascript to a control from a user control

2008-02-16T15:52:00.000-08:00

Here is a great solution to finding a control using FindControl method from a user control. TargetcontrolID is the public property for TextBoxFooExtender (User Control). _txt is the targeted TextBox assuming it is found.


    protected override void CreateChildControls()
    {
        txt = (TextBox)this.Parent.FindControl(TargetControlID);
        if (txt != null) {
            _txt.Attributes.Add("ondblclick", "alert('foo')");
        }
        base.CreateChildControls();
    }

How to show and hide CalendarExtender and CollapsiblePanel

2008-02-15T13:31:00.000-08:00

Here is the javascript for expanding or collapsing a collapsible panel:


        // Used for collapsible panels to toggle collapse or open
        function CollapsiblePanelExtender_Toggle(behaviorId)
        {
          var behavior = $find(behaviorId);
          if (behavior!=null) {
              if (behavior.get_Collapsed()==false) {
                try {behavior._doClose();} catch(e) { }
              }else if (behavior.get_Collapsed()==true) {
                try {behavior._doOpen();} catch(e) { }
              }
          }
        }
        // Used for calendar extenders to toggle show or hide
        function CalendarExtender_Toggle(behaviorId) {
              var behavior = $find(behaviorId);
              if (behavior!=null) {
                  if (behavior._isOpen==true) {
                    try {behavior.hide();} catch(e) { }
                  }else if (behavior._isOpen==false) {
                    try {behavior.show();} catch(e) { }
                  }
              }
        }

The Calendar show and hide behavior is above. Note: it may be helpful to use an empty label/image for the calendarExtender popupcontrolId to manage show/hide behavior.

Understanding Default Values for User Web Controls

2008-02-12T10:02:00.000-08:00

Understanding default values for User Web Controls can be confusing.
First, there is the DefaultValue for the code behind, which does not act as a default value, but as a default property value for the properties window. Here is the Default Property Value for the properties window set in the ascx.cs page:


    [Browsable(true)]
    [DefaultValue("")]
    public string Text
    {
        get { return Label.Text; }
        set {  Label.Text = value;
        }
    }

Now, what you really want is the default value for the control to be set in the ascx page as follows:


<asp:Label ID="Label" runat="server" Text=""></asp:Label>

You can then manipulate the value in the DataBind, CreateChildControls, or Property section. Be aware that the property section doesn't necessarily fire, hence the need to use the ascx properties.

Creating a ListItemCollection Template User Control

2008-02-10T11:48:00.000-08:00

Creating a ListItemCollection Template User Control. Here are the 3 files necessary. A link to the reference link is below.

First: The user control code-behind:


[DefaultEvent("SelectedIndexChanged"),
Designer("System.Web.UI.Design.WebControls.ListControlDesigner, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"),
ParseChildren(true, "Items"), ControlValueProperty("SelectedValue"),
DataBindingHandler("System.Web.UI.Design.WebControls.ListControlDataBindingHandler, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public partial class ComboBoxControl : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    private ListItemCollection m_Items;

  [DefaultValue((string)null), MergableProperty(false), 
  PersistenceMode(PersistenceMode.InnerDefaultProperty), 
  Editor("System.Web.UI.Design.WebControls.ListItemsCollectionEditor,System.Design, Version=2.0.0.0,Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a",
  typeof(UITypeEditor))]     
    public virtual ListItemCollection Items
    {
        get
        {
            if (this.m_Items == null)
            {
                this.m_Items = new ListItemCollection();
            }
            return this.m_Items;
        }
    }
    protected override void CreateChildControls()
    {
        if (this.m_Items == null)
        {
            this.m_Items = new ListItemCollection();
        }
        
        if (m_Items.Count>0) {
            foreach (ListItem item in m_Items)
            {
                _ComboBoxControl.Items.Add(item);
            }
        }
    }
    public override void DataBind()
    {
        CreateChildControls();
        ChildControlsCreated = true;
        _ComboBoxControl.DataBind();
        base.DataBind();
    }
}

Next, the User control


<%@ Control Language="C#" AutoEventWireup="true" CodeFile="ComboBoxControl.ascx.cs" Inherits="ComboBoxControl" %>
<asp:DropDownList ID="_ComboBoxControl" runat="server">
</asp:DropDownList>

And finally the aspx:


        <uc1:ComboBoxControl ID="ComboBoxControl1" runat="server">
        <Items>
            <asp:ListItem Value="Value1" Text="Text1" />
            <asp:ListItem Value="Value2" Text="Text2" />
            <asp:ListItem Value="Value3" Text="Text3" />
            <asp:ListItem Value="Value4" Text="Text4" />
        </Items>
        </uc1:ComboBoxControl>

Credit to: http://developers.de/blogs/damir_dobric/archive/2007/03/30/Implementing-Custom-UserControl-with-ListItem-collection.aspx

Installing CA Anti-virus with error on open

2008-02-08T00:22:00.000-08:00

I had a Vista problem installing the av_en_32.exe install wizard after I move the file from another computer. It gave some error that Windows cannot access the specified device, path, or file . You may not have the appropriate permissions to access them.

Solution: Right-click the icon and Unblock.

Web Control IDs INamingContainer to avoid duplicate IDs

2008-02-05T20:40:00.000-08:00

The ID property of the WebUserControl for controls that may be used mulitiple times in an aspx page should not be repeated. Simple implment the INamingContainer to prevent duplicate IDs as follows:


public partial class UCRepeater : System.Web.UI.UserControl, INamingContainer

Marker Interface - An interface that does not require explicit implementation.

Web User Control shortcut

2007-12-29T19:32:00.000-08:00

I just discovered a Web User Control shortcut for using your controls in apsx pages.
As per the reference link's example, add your implementation of this example:


        <add tagPrefix="scottgu" src="~/Controls/Footer.ascx" tagName="footer"/>
        <add tagPrefix="ControlVendor" assembly="ControlVendorAssembly"/>

All in the Web.config file in the elements.

Then you can reference it in aspx as

Reference: Link

Microsoft Visual Web, CSS, and Images link bug

2007-12-20T17:26:00.001-08:00

Here's a clue to avoid a bug with Microsoft Visual Web, CSS, and Images. I used the CSS style tool to add an image to an element, but the image would not show. The cause was a faulty link to the image.

Here is an example. I edit my StyleSheet.css in the css folder. I add an image from the brother folder named images. The link will say images/mypic.gif, but it is actually ../images/mypic.gif. Problem solved.

C# string is null or empty

2007-12-14T10:07:00.000-08:00

Here's another shortcut method to make sure the string is not null and not empty. What I find interesting is that using myString.length>0 is supposedly more efficient than myString != string.empty.


        if (!String.IsNullOrEmpty(myString))
        {
            myString = "myString != null && myString != string.Empty";
        }

C# string extract tag method

2007-12-14T09:23:00.000-08:00

This extracts a tagged string. For example, string findTagValue = extractTag ("Foo", "", ""); This would fetch Foo.


    private string extractTag(string original, string beginTag, string endTag)
    {
        string retVal = string.Empty;
        int begin = original.IndexOf(beginTag);
        int end = -1;
        if (begin > 0)
        {
            end = original.IndexOf(endTag, begin);
        }
        if ((begin > 0))
        {
            if ((end > begin))
            {
                retVal = original.Substring((begin+beginTag.Length), (end - begin-endTag.Length));
            }
        }
        return retVal;
    }

Handy C# tricks

2007-12-13T23:52:00.000-08:00

Here are some handy C# tricks to increase productivity.
First, the code:

//

        // Summary:

        //     Gets or sets a value that indicates whether the System.Web.UI.WebControls.MenuItem

        //     object is enabled, allowing the item to display a pop-out image and any child

        //     menu items.

//

        // Returns:

        //     true if the menu item is enabled; otherwise, false.

        [Browsable(true)]

        [DefaultValue(true)]

        public bool Enabled { get; set; }

The [Browsable(true)] allows the properties window to display the property or event.
Default value does as you would expect if the variable is not directly set
Short cut get and sets! Simple.

C# ASP.NET using JavaScript

2007-12-06T13:48:00.000-08:00

For ASP.NET, use the ClientScriptManager to register client scripts.

For example, in the Page_Load code behind I'll use:


ClientScript.RegisterClientScriptBlock(typeof(string), "MyScriptShow", "<script language=javascript>function showIt() { alert('showed it'); }</script>");

If the javascript was in a js file register it in the code behind with:


ClientScript.RegisterClientScriptBlock(typeof(string), "myScripts", "<script language='javascript' src='scripts/myScripts.js'></script>");

In the ASPX page I'll use;


        <asp:Button ID="Button1" runat="server" OnClientClick="showIt()" Text="Button" />

Resource links: link, link

Note: Use the ClientScript.RegisterClientScriptBlock or ClientScript.Register_x methods (since Page.Register_x methods are version 1.1)

Setting the path environmental variable in XP and Vista

2007-12-06T09:46:00.000-08:00

Setting the path environmental variable in XP and Vista.

It is often convenient to set the path environmental variable to call commands. For example, the "javac MyClass.java" command would use the javac command located in the path to compile the MyClass.java file to an executable. Here is how to set it up:

For Windows XP:
Start-> Control Panel -> System -> Advance Tab -> Environmental Variables.
Select Path -> Edit.
Append ";myPath" to environment variable, where myPath is the directory that contains your resources..
OK

For Windows Vista:
Start -> Control Panel -> System and Maintenance -> System -> Advanced system settings
click Continue
Select Environmental Variables
Select Path -> Edit.
Append ";myPath" to environment variable, where myPath is the directory that contains your resources..
OK

Using Google Web Toolkit gwt on Windows

2007-12-06T08:27:00.001-08:00

Here's a quick start to using Google's Web Toolkit or gwt.

1. Download latest gwt release at link.
2. Unzip gwt_x to target directory. I used C:/Program Files/Google.

Now to create Eclipse projects do the following:
1. Append to the path environmental variable the target directory such as ";C:/Program Files/Google/gwt_x" , where gwt_x is the gwt version installed.

To create an Eclipse project called "MyProject":
1. use the command prompt and navigate (cd) to the Eclipse workspace. Mine was "C:\work\workspace\".
2. Create a folder via "mkdir MyProject".
3. "cd MyProject"
4. Create project via "projectCreator -eclipse MyProject"
5. Create application via "applicationCreator -eclipse MyProject com.mycompany.client.MyApplication"

To open the Eclipse Project:
1. In Eclipse: File->Import->General->Existing Projects into workspace
2. Select the MyProject directory that you originally created.

Other References:
link, link

Creating a Web User Control

2007-12-04T13:57:00.000-08:00

Creating a Custom Web Control.
Within Visual Studio:
To keep organized, I create a company/website/user folder. Within the folder I create another folder named Controls. For example I'll have this directory structure: FooInc/Controls.

Within that folder, rt. click and Add New Item. Select the WebUserControl option. I'll name this one WebUserControl_DatePanel.ascx.

Switch to design view. Add a Panel (named Panel1 by default). Add a Label (named Label1 by default) within Panel1. Set Panel1's background to cyan for a custom feel.

In the load Event of WebUserControl_DatePanel.ascx, add the following:
Label1.Text = DateTime.Now.ToString();

Now save and close those files.

In your project, create a new Web Form named WebUser.aspx. Switch to design view.

From the Solution Explorer, drag the WebUserControl_DatePanel.ascx onto the page (much like adding a CSS file). Switch to Source View.

You will notice the following header:


<%@ Register Src="FooInc/Controls/WebUserControl_DatePanel.ascx" TagName="WebUserControl_DatePanel"
    TagPrefix="uc1" %>

You will also notice the following web user control in the body:


        <uc1:WebUserControl_DatePanel ID="WebUserControl_DatePanel1" runat="server" />

There it is. You can add custom functions at the web user control source if you want additional functionality.

How to implement Ajaxified details view hide on PageIndexChanging

2007-11-29T20:11:00.000-08:00

Previously I showed how to enable DetailsView with a Select button (link). But here is how to get rid of the DetailsView if Paging is enabled by using the PageIndexChanging method.


    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        // get rid of the details view
        DetailsView1.DataSource = null;
        DetailsView1.DataBind();

        GridView1.PageIndex = e.NewPageIndex;
        GridView1.DataBind();
    }

To Ajaxify it within an update panel, add a Trigger for the Gridview1 object and the PageIndexChanging event.

Generate Random numbers

2007-11-29T11:17:00.000-08:00

Here's a quick one on how to generate random numbers. link


Random rnd = new Random();
int myRandom = rnd.Next();

Implementing Dynamic Hyperlink of Current Page

2007-11-29T09:32:00.001-08:00

Here's how to implement a dynamic HyperLink of the current page based on the current pages title and current URL without the query string parameters. This is located in the Master Page.


    protected void Page_Load(object sender, EventArgs e)
    {
        hlPageTitle.Text = Page.Title.ToString();
        // old way would fetch query string paramaters
        //hlPageTitle.NavigateUrl = Request.Url.AbsoluteUri.ToString();
        hlPageTitle.NavigateUrl = Request.Url.GetLeftPart(UriPartial.Path);
    }

Reference link.

Fixing WebForms.PageRequestManagerServerErrorException Status code 500

2007-11-26T10:27:00.000-08:00

Here's a fix for the error WebForms.PageRequestManagerServerErrorException Status code 500.
I modified the MasterPage's ScriptManager as follows:


                    <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="false">
                    </asp:ScriptManager>

UPDATE: This might fix the error, but it limits the functionality by not allowing Partial Page Rendering. This may not be acceptable. Here is a hint to avoid breaking the AJAX:

Hint: Be careful when changing Control names. The IDE won't catch the name change in the Extenders section of the TargetControlID.

How to implement Select on a GridView1 with Paging enabled.

2007-11-25T12:01:00.000-08:00

How to implement Select on a GridView1 with Paging enabled based on a DataTable.


    protected void GridView1_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
    {
        // e.NewSelectedIndex -> 0 to n
        // GridView1.PageCount -> (n-1) always 
        // GridView1.PageIndex -> 0 to Page#
        int rowN = 1 + ((GridView1.PageCount-1) * GridView1.PageIndex + e.NewSelectedIndex);
        DetailsView1.HeaderText = "Details View of Row "+ rowN.ToString();
        DetailsView1.PageIndex = rowN - 1;
        GridView1.SelectedIndex = rowN - 1;
        DetailsView1.DataSource = Cache["dt"];        
        DetailsView1.DataBind();
    }

How to enable paging on a GridView that is bound to a DataTable.

2007-11-25T11:46:00.000-08:00

How to enable paging on a GridView that is bound to a DataTable. On the GridView, simply


    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GridView1.PageIndex = e.NewPageIndex;
        GridView1.DataSource = Cache["dt"];
        GridView1.DataBind();
    }

link

Using Yahoo Mail Web Service hints

2007-11-17T10:19:00.000-08:00

This should help you use Yahoo Mail Web Service for C# .NET.
First, go to link and download code sample for C#.
Second, use the APIs at link. I prefer the html link.
Third, get an application id at link. Be sure that this is the destination page where you will acquire the credentials using Request.QueryString[xTag].
Fourth, the above doesn't really explain a detail that will let the Web Service actually return Messages. Make sure that the xTagIsSpecified boolean is set before the request!
NOTE: The code sample below only works with premium accounts. Accounts link.


                // <ListMessages>                
                // ListMessages, lists the messages in a given folder.
                ListMessages listRequest = new ListMessages();
                listRequest.fid = "Inbox";
                listRequest.startMid = 0;
                listRequest.startInfo = 0;
                listRequest.numMid = 10;
                listRequest.numInfo = 1;
                listRequest.startMidSpecified = true;
                listRequest.startInfoSpecified = true;
                listRequest.numMidSpecified = true;
                listRequest.numInfoSpecified = true;
                ListMessagesResponse listResponse = ymwsInstance.ListMessages(listRequest);
                retVal += string.Format("<br />Listed folder <b>{0}</b>, found <b>{1}</b> message IDs.<br />",
                    listResponse.folder.folderInfo.name, listResponse.mid.Length);
                string[] listedMed = ymwsInstance.ListMessages(listRequest).mid;                
                // </ListMessages>

Well documented C# code sample

2007-11-14T17:09:00.001-08:00

Well documented C# code sample demonstrates region, summary, and parameter documentation.


#region well documented sample method sample    
        /// <summary>
        /// Saves the form size when it is resized.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void SampleBrowser_SizeChanged(object sender, EventArgs e)
        {
            Properties.Settings.Default.FormClientSize = this.ClientSize;
        }

        /// <summary>
        /// Saves all settings when form is closed.
        /// </summary>
#endregion

Note: In addition to "param", one can use:


    /// <returns>State of log in</returns>

Also: The #endregion must be on a new line!

Caching Methods in ASP.NET 2.0

2007-11-13T10:31:00.001-08:00

How To Cache

Method	Implementation	Sample uses
Programatic Caching	Set: Cache.Insert("UniqueKey", myData, null, DateTime.Now.AddMinutes(5), System.Web.Caching.Cache.NoSlidingExpiration); Get: Cache["UniqueKey"].ToString();
Session State Caching	Set: Session.Add("UniqueKey", myData); Get: Session["UniqueKey"];
Caching to Disk	Application Cache Block
Caching to Database	CodeProject Article

link

Modifying labels in MasterPage From MasterPage user Page

2007-11-12T08:47:00.000-08:00

First, here is how to modify a label in the MasterPage from the MasterPage user Page:


        Label mpLabel = (Label)Master.FindControl("lblPageTitle");
        if (mpLabel != null)
        {
            mpLabel.Text = this.Title.ToString();
        }

link

Setup an email form for .NET 2.0

2007-11-05T20:08:00.000-08:00

Here is how I setup the email action for .NET 2.0. I included "using System.Net.Mail;" and "using System.Net;"


        string sTo = "foo@foo.com";
        string sFrom = txtFrom.Text.Trim();
        string sSubject = "inforequest message" + DateTime.Now.ToLongDateString();
        string sBody = txtContent.Text.Trim();
        lblStatus.Text = "Sending... please wait";
        MailMessage msg = new MailMessage(sFrom, sTo, sSubject, sBody);
        msg.IsBodyHtml = false;
        SmtpClient mailObj = new SmtpClient("mail.foo.com");
        mailObj.Credentials = new NetworkCredential("user", "secret"); 
        mailObj.Send(msg);
        lblStatus.Text = "Sent " + msg.Subject + " to " + msg.To;

references: link
Note: I used "localHost" instead of "mail.foo.com".

Adding a Checkbox Column to a GridView and checking if it is checked.

2007-10-25T12:54:00.000-07:00

In my project I bind a DataTable to a Gridview. I have two fields in my DataTable: (bool) isChecked and (string) Value. Below I bind the data to those fields in the first two columns. The last Column I used a TemplateField and ItemTemplate to create a CheckBox row that is editable.


                <asp:GridView ID="GridView1" runat="server" 
                              OnDataBound="GridView1_DataBound" 
                              OnSelectedIndexChanged="GridView1_SelectedIndexChanged" 
                              AutoGenerateColumns="False" >
                    <Columns>
                        <asp:CheckBoxField DataField="isChecked" HeaderText="Select" />
                        <asp:BoundField DataField="Value" HeaderText="Value" />
                        <asp:TemplateField HeaderText="Custom Select">
                            <ItemTemplate>
                                <asp:CheckBox ID="chkSelect" runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>                        
                    </Columns>
                </asp:GridView>

Once the user edits the Custom Select checkboxes and pushes the button (btnSumbit), I read which fields are checked. If checked, I read from a Hashtable the value associated with the key.


    protected void btnSubmit_Click(object sender, EventArgs e)
    {
            string sQueryString = "http://foo?";
            // load hashtable with key values
            Hashtable vhtTags = (Hashtable)Cache["htTags"];
            bool isChecked;
            // parse through to see what values are selected in gridview
            foreach (GridViewRow vRow in GridView1.Rows)
            {
                isChecked = ((CheckBox)vRow.FindControl("chkSelect")).Checked;
                if (isChecked)
                {
                    string skey = vRow.Cells[1].Text.Trim();
                    sQueryString += vhtTags[skey].ToString();
                }
            }
            lblResult.Text = sQueryString;
        }        
    }

Notes: Since the first check column is only for demonstration and the last column is not bound because the default values are false. For the sake of brevity, error checking is left out.
Reference: link

Reversing the Keys and Values in a Hashtable

2007-10-24T12:01:00.000-07:00

Here's how to reverse the Keys and Values in a Hashtable. I use the results and overwrite the original ht.Adds.
The results are output into the TextBox txtReversed.Text


protected void btnReverseHash_Click(object sender, EventArgs e)
    {
        Hashtable ht = new Hashtable();
        ht.Add("a1", "Ask");
        ht.Add("a2", "Ask what your country can do for you");
        ht.Add("a3", "Ask what you can do for your country");
        IDictionaryEnumerator _enum = ht.GetEnumerator();
        string sOut = "";
        const string _FRONT = "ht.Add(";
        const string _END = ");\n";
        const string _Q = "\"";
        const string _CS = ", ";
        while (_enum.MoveNext())
        {
            sOut += _FRONT + _Q + _enum.Value.ToString() + _Q + _CS
                          + _Q + _enum.Key.ToString() + _Q + _END;
        }
        txtReversed.Text = sOut;
}

Sorting a GridView that is detached from database and put in a cache

2007-10-17T13:12:00.000-07:00

First, the GridView needs to have sorting enabled and a sorting method:


                    <asp:GridView ID="GridView2" runat="server"
                        OnSorting="GridView2_Sorting" AllowSorting="True">                        
                    </asp:GridView>

Next, the page load and sorting method need to be implemented. I loaded my data from another GridView at the load. There is a Label that is also used. This code is similar to this reference link.


    protected void Page_Load(object sender, EventArgs e)
    {
        DataView myDataView;

        // Retrieve the DataView object from Cache. If not exist, then add DataView object to the Cache.

        myDataView = (DataView)Cache["MyDataSet"];

        if (myDataView == null)
        {
            myDataView = getTable().DefaultView;
            Cache["MyDataSet"] = myDataView;
            myDataView.Sort = myDataView.Table.Columns[0].ToString() + " ASC";
            lblCacheMsg.Text = "Dataset created explicitly";
        }
        else
        {
            lblCacheMsg.Text = "Dataset retrieved from cache";
        }
        GridView2.DataSource = myDataView;
        GridView2.DataBind();
    }

// Verbose sort version
    protected void GridView2_Sorting(object sender, GridViewSortEventArgs e)
    {
        DataView Source = (DataView)Cache["MyDataSet"];
        string direction = " DESC";
        string curDirecton = Source.Sort.ToString().ToUpper();
        if (curDirecton.Contains(direction))
        {
            direction = ASC;
        }
        else
        {
            direction = DESC;
        }        
        Source.Sort = e.SortExpression + " " + direction;
        Cache["MyDataSet"] = Source;
        GridView2.DataSource = Source;
        GridView2.DataBind();
        lblE.Text = direction;
    }
    private DataTable getTable()
    {
        DataTable retVal;
        DataTableHelper dth = new DataTableHelper(GridView1);
        retVal = dth.getDataTable();
        return retVal;
    }

Modifying display of your GridView with CSS

2007-10-08T11:54:00.000-07:00

If you manage multiple GridViews that you want to have the same format, use CSS classes. In the Styles section of the GridView properties there are:

AlternatingRowStyle
EditRowStyle
EmptyDataRowStyle
FooterStyle
HeaderStyle
PagerStyle
RowStyle
SelectedRowStyle

In this example I'll create classes in my CSS file as such:

.tableAnalysisRow {
border-right:#000 thin solid;
border-bottom:#000 thin solid;
background:#fff;
color:#000;
border-top:#000 thin solid;
border-left:#000 thin solid;
padding:2px 2px 3px 4px;
}
.tableAnalysisAlternatingRow {
border-right:#000 thin solid;
border-bottom:#000 thin solid;
background:#DCDCDC;
color:#000;
border-top:#000 thin solid;
border-left:#000 thin solid;
padding:2px 2px 3px 4px;
}
.tableAnalysisHeader {
border-right:#000 thick solid;
border-bottom:#000 thick solid;
background:#DCDCDC;
color:#000;
border-top:#000 thick solid;
border-left:#000 thick solid;
font-weight:700;
border-collapse:separate;
border-color:#000;
padding: 2px 2px 3px 4px;
}

Now just modify the Class property in the appropriate Gridview Style property like the following:


                <asp:GridView ID="GridView1" runat="server" >
                    <RowStyle CssClass="tableAnalysisRow" />
                    <HeaderStyle CssClass="tableAnalysisHeader" />
                    <AlternatingRowStyle CssClass="tableAnalysisAlternatingRow" />
                </asp:GridView>

The result GridView is here.

Swapping GridView DataSourceID from DataSource

2007-10-06T23:52:00.000-07:00

Here's the simple code for swapping the GridView back to DataSourceID from DataSource:


    protected void DropDownListListsInUser_SelectedIndexChanged(object sender, EventArgs e)
    {
        GridViewStocksInList.DataSource = null;
        GridViewStocksInList.DataSourceID = SqlDataSourceGetStocksInList.ID;
        GridViewStocksInList.DataBind();
    }

The solution came from here.
It suggested studying this.

Help user redirect to secure target page after login and avoid extra navigation

2007-10-05T19:54:00.000-07:00

Here's a solution for when the user needs to log in before accessing a secure page. This allows the user to avoid going through the menu system to go to the original page desired. I avoid some kind of error by using the false parameter in the redirect. The querystring of note is ReturnUrl.


    protected void Page_Load(object sender, EventArgs e)
    {            
        if (User.Identity.IsAuthenticated == false)
        {
            Response.Redirect("Login.aspx?ReturnUrl=DesiredPage.aspx", false);
        }
        else
        {
            MembershipUser user = Membership.GetUser().ProviderUserKey.ToString();
        }
    }

RedirectFromLoginPage Method

Using a GridView to make calculations and avoid Database changes by merging DataTables and using PrimaryKey.

2007-10-04T08:46:00.000-07:00

Merging DataTables named dt and dt2.

Before I show the diffences, here are the contents of dt (Figure 1) and dt2 (Figure 2):

Symbol	Name	Exchange
FRE	Freddie Mac	NYSE
FRE/PB	Freddie Mac	NYSE
FRE/PF	Freddie Mac	NYSE
FRE/PG	Freddie Mac	NYSE
FRE/PH	Freddie Mac	NYSE

Figure 1. dt

Symbol	EPS Growth	Lower Price Target	Lower % Target	Upper Price Target	Upper % Target
FRE	FRE	FRE	FRE	FRE	FRE
FRE/PB	FRE/PB	FRE/PB	FRE/PB	FRE/PB	FRE/PB
FRE/PF	FRE/PF	FRE/PF	FRE/PF	FRE/PF	FRE/PF
FRE/PG	FRE/PG	FRE/PG	FRE/PG	FRE/PG	FRE/PG
FRE/PH	FRE/PH	FRE/PH	FRE/PH	FRE/PH	FRE/PH

Figure 2. dt2

In my project I want to use a GridView and append calculated data without changing the database.
My solution is to read the GridView into a DataTable, dt. Then, I make calculations from a PrimaryKey of dt and use the same PrimaryKey for dt2 while adding actual calculations (EPS Growth, Lower Price Target, ... in production version). The final step is to Merge the datatables with dt.Merge(dt2). The result is shown in Figure 3.

Symbol	Name	Exchange	EPS Growth	Lower Price Target	Lower % Target	Upper Price Target	Upper % Target
FRE	Freddie Mac	NYSE	FRE	FRE	FRE	FRE	FRE
FRE/PB	Freddie Mac	NYSE	FRE/PB	FRE/PB	FRE/PB	FRE/PB	FRE/PB
FRE/PF	Freddie Mac	NYSE	FRE/PF	FRE/PF	FRE/PF	FRE/PF	FRE/PF
FRE/PG	Freddie Mac	NYSE	FRE/PG	FRE/PG	FRE/PG	FRE/PG	FRE/PG
FRE/PH	Freddie Mac	NYSE	FRE/PH	FRE/PH	FRE/PH	FRE/PH	FRE/PH

Figure 3.

If you simply Merge with dt.Merge(dt2), you would get the same result as long as the PrimaryKey is set in dt. However, without setting the PrimaryKey you get the result in Figure 4.

Symbol	Name	Exchange	EPS Growth	Lower Price Target	Lower % Target	Upper Price Target	Upper % Target
FRE	Freddie Mac	NYSE
FRE/PB	Freddie Mac	NYSE
FRE/PF	Freddie Mac	NYSE
FRE/PG	Freddie Mac	NYSE
FRE/PH	Freddie Mac	NYSE
FRE			FRE	FRE	FRE	FRE	FRE
FRE/PB			FRE/PB	FRE/PB	FRE/PB	FRE/PB	FRE/PB
FRE/PF			FRE/PF	FRE/PF	FRE/PF	FRE/PF	FRE/PF
FRE/PG			FRE/PG	FRE/PG	FRE/PG	FRE/PG	FRE/PG
FRE/PH			FRE/PH	FRE/PH	FRE/PH	FRE/PH	FRE/PH

Figure 4.

In my implementation I use:
dt.Merge(dt2, false, MissingSchemaAction.Ignore);
This will avoid preserving changes and ignore taking action when there is a missing schema.

Loading a GridView into a DataTable and then back to another GridView

2007-10-03T17:10:00.000-07:00

First, Loading a GridView into a DataTable, dt:


    private void initDataTable()
    {
        
        int i = 0;
        int j = 0;
        int totRow = GridView1.Rows.Count;
        int totCol = GridView1.Rows[0].Cells.Count;
        // Set the table headers
        string[] arrHeaders = {"Symbol","Name","Exchange" };
        // Get the table headers
        for (j = 0; j < totCol; j++)
        {
            // The commented line would work if the Gridview had Column HeaderText
            //dt.Columns.Add(new DataColumn(GridView1.Columns[col].HeaderText, typeof(string)));

            // Instead I use the Headers array, arrHeaders
            dt.Columns.Add(new DataColumn(arrHeaders[j].ToString(), typeof(string)));
        }
        DataRow dr;
        for (i = 0; i < totRow; i++)
        {
            dr = this.dt.NewRow();            
            for (j = 0; j < totCol; j++)
            {
                dr[j] = GridView1.Rows[i].Cells[j].Text;
            }
            this.dt.Rows.Add(dr);
        }
    }

Then back to another GridView:


    private void fillGridView2()
    {
        if (dt.Rows.Count > 0)
        {
            GridView2.DataSource = dt;
            GridView2.DataBind();
        }
        else
        {
            dt.Rows.Add(dt.NewRow());
            GridView2.DataSource = dt;
            GridView2.DataBind();

            int TotalColumns = GridView2.Rows[0].Cells.Count;
            GridView2.Rows[0].Cells.Clear();
            GridView2.Rows[0].Cells.Add(new TableCell());
            GridView2.Rows[0].Cells[0].ColumnSpan = TotalColumns;
            GridView2.Rows[0].Cells[0].Text = "No Record Found";
        }
    }

The no record found code was from this link.

Connecting to Kensoft.net SQL Server 2005 database

2007-09-27T17:04:00.002-07:00

The side note for this is that the database name in Kensoft has an '_' in it, not a '.'.


<connectionStrings>
        <!--<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\MyDatabase.mdf;Integrated Security=True; User Instance=True" providerName="System.Data.SqlClient"/>
     -->
  <add name="ConnectionString" connectionString="Data Source=mssql2005.kensoft.net;Database=myDatabase;uid=myUserId;pwd=myPassword" providerName="System.Data.SqlClient" />
</connectionStrings>