Data Binding to List Controls

dejawoo · July 3rd, 2004, 09:51 AM

hi there,

I ve been reading the Book Professional ASP.Net 1.0 more precisely chapter 7. on List controls and data binding. One thing that seems for me obscure I d like pose you . Hope someone can help with this. The book states that <%# DataBinder.Eval(Container.DataItem, "field-name") %> makes a performance hit i.e. an overhead so it should be avoided unless we deal with formatting. In my code I have just have fields that I have defined in ItemTemplate for DataList so there s a hyperlink defined which takes it caption from the datasource field. So there s nothing with formatting . I try to use Container.DataItem("field-name") but it gives error.it says it should expecting a method instead of property..? I just try to avoid from the overhead.. but I can handle.. the code in books reveal it should quite work well.. my great pre-thanx

alyeng2000 · July 3rd, 2004, 04:51 PM

just bind properties Text,Value fields like this way
DataTextField="CategoryName" DataValueField="CategoryId"

Ahmed Ali
Software Developer

melvik · July 3rd, 2004, 10:54 PM

This is a simple linkBox Binding sample using SQL Server 2000 [u]Northwind Database</u>

Code:

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<Script Runat="Server">
  void Page_Load( Object s, EventArgs e )
  {
    SqlConnection myConnection;
    SqlCommand myCommand;
    myConnection = new SqlConnection( "Server=Localhost;uid=sa;Database=Northwind" );
    myCommand = new SqlCommand( "Select CategoryName from Categories", myConnection );
    myConnection.Open();
    myDataList.DataSource = myCommand.ExecuteReader();
    myDataList.DataBind();
    myConnection.Close();
  }
</Script>

<html>
<head><title>Categories</title></head>
<body>

<form Runat="Server">
<asp:DataList id="myDataList" Runat="Server">
  <ItemTemplate>
        <%# DataBinder.Eval( Container.DataItem, "CategoryName" ) %>
  </ItemTemplate>
</asp:DataList>
</form>

</body>
</html>

HTH.

Always:),
Hovik Melkomian.