C# Asp.net Dropdownlist 选定的索引已更改且 TextChanged 事件未触发？（C＃）
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Asp.net Dropdownlist selected index changed AND TextChanged Events not Fire? (C#)
提问by Sagotharan
I am new to ASP>NET(C#). But I am using Winform before.
我是 ASP>NET(C#) 的新手。但我以前使用过Winform。
In my Project I have two dropdown list. if i change the one,.. the second will change auto.
在我的项目中，我有两个下拉列表。如果我改变一个，..第二个将改变自动。
But even event also not firing in ASP.net. Without event how to i manage that?.
但即使事件也不会在 ASP.net 中触发。没有事件我如何管理？。
<div id="Div1" class="ui-content ui-body-a" runat="server">
<asp:dropdownlist id="ddlOutlet" runat="server" autopostback="True" onselectedindexchanged="ddlOutlet_SelectedIndexChanged"
ontextchanged="ddlOutlet_TextChanged">
</asp:dropdownlist>
<br />
<asp:dropdownlist id="ddlServedAt" runat="server">
</asp:dropdownlist>
<br />
<asp:button id="btnLogin" runat="server" text="LogIn" />
</div>
C#
C＃
I already Added items in both dropdown list in page load event. But When I change the ddlOutlet selected index changed Event not firing. So I tried to TextChanged Events Also. But nothing happened. What is problem?.
我已经在页面加载事件的两个下拉列表中添加了项目。但是当我更改 ddlOutlet 选择的索引时，事件未触发。所以我也尝试 TextChanged 事件。但什么也没发生。什么问题？。
Page Load Event -
页面加载事件 -
protected void Page_Load(object sender, EventArgs e)
{
HelpingFunctions hp = new HelpingFunctions();
string id = Request.QueryString["id"];
MySqlConnection connection = new MySqlConnection("server=192.168.1.100;username=mcubic;password=mcs@2011$;database=mcubic;");
string query = "SELECT c.Outlet_Master_Name,d.Fbserved_Served FROM mcs_user a, mcs_user_outlet b,outlet_master c,fb_served d WHERE a.Mcs_User_Id='" + id + "' and"
+ " a.Mcs_User_Id = b.Mcs_User_Outlet_User_Id and c.Outlet_Master_Id = b.Mcs_User_Outlet_Outlet_Id and c.Outlet_Master_Id=d.Fbserved_outletid";
MySqlCommand command = new MySqlCommand(query, connection);
connection.Open();
MySqlDataReader Reader = command.ExecuteReader();
while (Reader.Read())
{
ddlOutlet.Items.Add(Reader[0].ToString());
ddlServedAt.Items.Add(Reader[1].ToString());
}
connection.Close();
}
Selected Item -
所选项目 -
protected void ddlOutlet_SelectedIndexChanged(object sender, EventArgs e)
{
MySqlConnection connection = new MySqlConnection("server=192.168.1.100;username=mcubic;password=mcs@2011$;database=mcubic;");
string query = "select Fbserved_Served from fb_served where Fbserved_outletid = (select Outlet_Master_Id from outlet_master where Outlet_Master_Name ='" + ddlOutlet.SelectedItem.ToString() + "')";
MySqlCommand command = new MySqlCommand(query, connection);
connection.Open();
MySqlDataReader Reader = command.ExecuteReader();
while (Reader.Read())
{
ddlServedAt.SelectedItem.Value = Reader[0].ToString();
}
connection.Close();
}
I read some same issue problem solutions, but they told to set AutoPostBack="True". I checked that also.
我阅读了一些相同的问题解决方案，但他们告诉设置 AutoPostBack="True"。我也检查过。
I don't know why ASP.net hard to Event firing also?.
我不知道为什么 ASP.net 也很难触发事件？。
UPDATED QUESTION
更新的问题
In my Project,.. I am using jquerymobile(http://jquerymobile.com/) with ASP.Net and mysql. I have two drop down list controls and ONE button.
在我的项目中，.. 我在 ASP.Net 和 mysql 中使用 jquerymobile(http://jquerymobile.com/)。我有两个下拉列表控件和一个按钮。
But When I change the ddlOutlet selected index changed Event not firing. After the button Click the Events Are fired Correctly. But Before that They not fire. I do't know Why its happen.
但是当我更改 ddlOutlet 选择的索引时，事件未触发。单击按钮后，事件被正确触发。但在此之前他们不会开火。我不知道为什么会发生。
I Give my Complete Code Below.
我在下面给出了我的完整代码。
My Complete ASPX File :-
我的完整 ASPX 文件：-
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="OutLet.aspx.cs" Inherits="MobileApp.OutLet" %>
<!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></title>
<meta name="viewport" content="width=device-width; height=device-height; initial-scale=1.0; maximum-scale=1.5; user-scalable=no;" />
<link href="Styles/jquery.mobile-1.0b3.css" rel="stylesheet" type="text/css" />
<script src="Scripts/jquery-ui-1.8.16.custom.min.js" type="text/javascript"></script>
<script src="Scripts/jquery-1.6.2.min.js" type="text/javascript"></script>
<script src="Scripts/jquery.mobile-1.0b3.js" type="text/javascript"></script>
</head>
<body>
<form id="form1" runat="server" data-ajax="false">
<div id="mainheader" class="ui-header-fixed ui-bar-a">
</div>
<div id="Div1" class="ui-content ui-body-a" runat="server">
<%-- <asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>--%>
<asp:DropDownList ID="ddlOutlet" runat="server"
AutoPostBack="True" onselectedindexchanged="ddlOutlet_SelectedIndexChanged"
ontextchanged="ddlOutlet_TextChanged">
</asp:DropDownList>
<br />
<asp:DropDownList ID="ddlServedAt" runat="server" AutoPostBack="True">
</asp:DropDownList>
<br />
<asp:Button ID="btnLogin" runat="server" Text="LogIn"
onclick="btnLogin_Click" />
<%-- </ContentTemplate>
</asp:UpdatePanel> --%>
</div>
</form>
</body>
</html>
my Code -
我的代码 -
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using MySql.Data.MySqlClient;
namespace MobileApp
{
public partial class OutLet : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
HelpingFunctions hp = new HelpingFunctions();
string id = Request.QueryString["id"];
if (!Page.IsPostBack)
{
MySqlConnection connection = new MySqlConnection("server=192.168.1.100;username=mcubic;password=mcs@2011$;database=mcubic;");
string query = "SELECT c.Outlet_Master_Name,d.Fbserved_Served FROM mcs_user a, mcs_user_outlet b,outlet_master c,fb_served d WHERE a.Mcs_User_Id='" + id + "' and"
+ " a.Mcs_User_Id = b.Mcs_User_Outlet_User_Id and c.Outlet_Master_Id = b.Mcs_User_Outlet_Outlet_Id and c.Outlet_Master_Id=d.Fbserved_outletid";
MySqlCommand command = new MySqlCommand(query, connection);
connection.Open();
MySqlDataReader Reader = command.ExecuteReader();
while (Reader.Read())
{
ddlOutlet.Items.Add(Reader[0].ToString());
ddlServedAt.Items.Add(Reader[1].ToString());
}
connection.Close();
}
}
protected void ddlOutlet_SelectedIndexChanged(object sender, EventArgs e)
{
MySqlConnection connection = new MySqlConnection("server=192.168.1.100;username=mcubic;password=mcs@2011$;database=mcubic;");
string query = "select Fbserved_Served from fb_served where Fbserved_outletid = (select Outlet_Master_Id from outlet_master where Outlet_Master_Name ='" + ddlOutlet.SelectedItem.ToString() + "')";
MySqlCommand command = new MySqlCommand(query, connection);
connection.Open();
MySqlDataReader Reader = command.ExecuteReader();
while (Reader.Read())
{
ddlServedAt.SelectedValue = Reader[0].ToString();
}
connection.Close();
}
protected void ddlOutlet_TextChanged(object sender, EventArgs e)
{
//MySqlConnection connection = new MySqlConnection("server=192.168.1.100;username=mcubic;password=mcs@2011$;database=mcubic;");
//string query = "select Fbserved_Served from fb_served where Fbserved_outletid = (select Outlet_Master_Id from outlet_master where Outlet_Master_Name ='" + ddlOutlet.SelectedItem.ToString() + "')";
//MySqlCommand command = new MySqlCommand(query, connection);
//connection.Open();
//MySqlDataReader Reader = command.ExecuteReader();
//while (Reader.Read())
//{
// ddlServedAt.SelectedItem.Value = Reader[0].ToString();
//}
//connection.Close();
}
protected void btnLogin_Click(object sender, EventArgs e)
{
}
}
}
采纳答案by Pankaj
try by Adding Page.IsPostBackin your page_Loadevent...
尝试通过添加Page.IsPostBack您的page_Load活动...
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
//your page load code.....
}
}
EDIT - 1
编辑 - 1
Sample Code of ASPX page in Web Application
Web应用中ASPX页面的示例代码
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList id="id1" runat="server" AutoPostBack="true"
onselectedindexchanged="id1_SelectedIndexChanged">
<asp:ListItem Text="1" Value="1"></asp:ListItem>
<asp:ListItem Text="2" Value="2"></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList id="id2" runat="server"></asp:DropDownList>
</div>
</form>
</body>
</html>
Sample code of code behind in Web Application
Web 应用程序中的代码示例代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebApplication1
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void id1_SelectedIndexChanged(object sender, EventArgs e)
{
}
}
}
Sample code of ASPX page in Website
网站中ASPX页面的示例代码
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default4.aspx.cs" Inherits="Default4" %>
<!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></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList id="id1" runat="server" AutoPostBack="true"
onselectedindexchanged="id1_SelectedIndexChanged">
<asp:ListItem Text="1" Value="1"></asp:ListItem>
<asp:ListItem Text="2" Value="2"></asp:ListItem>
</asp:DropDownList>
<asp:DropDownList id="id2" runat="server"></asp:DropDownList>
</div>
</form>
</body>
</html>
Sample code of Code behind in Website
网站后台代码示例代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class Default4 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void id1_SelectedIndexChanged(object sender, EventArgs e)
{
}
}
回答by Sonhacker
Create the drop down list(the one that changes the content of the other one)
创建下拉列表（改变另一个内容的那个）
Activity: <asp:DropDownList ID="cmbActivity" runat="server" OnSelectedIndexChanged="cmbActivity_SelectedIndexChanged" AutoPostBack="true" />
Then in your C#, your load event should be like this
然后在你的 C# 中，你的加载事件应该是这样的
if (Session["staffId"] == null)
{
Response.Redirect("~/login.aspx");
}
else
{
if (!IsPostBack)
{
cmbActivity.DataSource = a;
cmbActivity.DataTextField = "activityName";
cmbActivity.DataValueField = "activiyId";
}
}
Your selectedIndex_Changed method still remains the same. This should work. Have more than one item in the list to be sure. I hope this helps
您 selectedIndex_Changed 方法仍然保持不变。这应该有效。确保列表中有不止一项。我希望这有帮助
回答by w00ngy
OP already had this in his question, but I was missing autopostback="True"
OP在他的问题中已经有了这个，但我错过了 autopostback="True"
