If you have a
GridView, DataGrid, DetailsView,
FormView,
DataList or
Repeater bound using
DataSourceID you should never touch the controls collection in
Page_Init or
Page_PreInit. If you do this your declarative data-binding will be lost on any outside of the control post-back.
How to check this?
Example:
aspx<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:Button ID="Button1" Text="Button1" runat="server" />
<asp:GridView ID="GridView1" AllowPaging="true" DataSourceID="AccessDataSource1"
runat="server">
</asp:GridView>
<asp:DetailsView ID="DetailsView1" DataSourceID="AccessDataSource1" AllowPaging="true"
runat="server">
</asp:DetailsView>
<asp:FormView ID="FormView1" DataSourceID="AccessDataSource1" AllowPaging="true"
runat="server">
<ItemTemplate>
ProductID :
<%# Eval("ProductID") %>
</ItemTemplate>
</asp:FormView>
<asp:DataList ID="DataList1" DataSourceID="AccessDataSource1" runat="server">
<ItemTemplate>
...