AutoPostBack=“true” doesn't work for DropDownList with DataSource
Question
I have following *.aspx page
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test.aspx.cs" Inherits="Admin_Test" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form2" runat="server">
<div>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" DataTextField="Name" DataValueField="FieldKey" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
and *.aspx.cs page
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 System.Collections.Generic;
using System.Linq;
public partial class Admin_Test : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DataClassesDataContext datacontext = new DataClassesDataContext();
DropDownList1.DataSource = datacontext.GetAllDepartments(false);
DropDownList1.DataBind();
}
}
}
When I change the value in dropdownList (in browser), it does PostBack, but it selects the first item of list after PostBack - it doesn't save my value.
GetAllDepartments(isDeleted) is a stored procedure, it returns a List of objects with two properties - FieldKey and Name.
3 answers
solution1
1 2010-08-31 03:52:56
You can set the event like this:
protected void Page_Load(object sender, EventArgs e)
{
DropDownList1.SelectedIndexChanged += new System.EventHandler(this.On_SelectedIndexChanged);
if (!IsPostBack)
{
DataClassesDataContext datacontext = new DataClassesDataContext();
DropDownList1.DataSource = datacontext.GetAllDepartments(false);
DropDownList1.DataBind();
}
}
solution2
1 2010-08-31 15:53:10
It seem to me that there is something wrong with the ViewState. Have you somehow disabled ViewState?
solution3
0 ACCPTED 2011-03-15 23:45:33
我找到了一个答案-* .dbml已过时，GetAllDepartments的每个FieldKey都返回0-因此，存在项的重复值。
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