Modifying the contents of a GridView after DataBinding

This is more than bare functionality, but it can be simplified by eliminating the contents in foreach brackets.

protected void  GridView1_DataBound(object sender, EventArgs e)
{
       foreach (GridViewRow dgrow in GridView1.Rows)
       {
           String myString, myPattern;
           Boolean result;
           myPattern = txtSearch.Text;
           myString = dgrow.Cells[0].Text;
           result = true;

           if (isEndsWith == true)
           {
               if (myPattern.Length > 0)
               {
                   result = myString.EndsWith(myPattern);
                   dgrow.Cells[0].Text = myString.Substring(0, myString.LastIndexOf(myPattern))
                       + HighlightText(myPattern, myString.Substring(myString.LastIndexOf(myPattern)));
               }
               else result = false;
               if (result == false)
                   dgrow.Cells[0].Visible = false;
           }
           else
           {
               if (isStartsWith)
               {
                   if (myPattern.Length > 0)
                   {
                       result = myString.StartsWith(myPattern);
                       dgrow.Cells[0].Text = HighlightText(myPattern, myString.Substring(0,myPattern.Length)) + myString.Substring(myPattern.Length, myString.Length-myPattern.Length);
                       dgrow.Cells[0].Visible = true;
                   }
               }
               else
               {
                   dgrow.Cells[0].Text = HighlightText(myPattern, myString);
                   dgrow.Cells[0].Visible = true;
               }
           }
       }
}