帮我看看c#的这个程序我如何修改才能在网页上输出"你选择的是第..项"

来源:百度知道 编辑:UC知道 时间:2024/05/28 18:15:04
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;

public partial class _Default : System.Web.UI.Page
{

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DropDownList1.Items.Add("爱情转义");
DropDownList1.Items.Add("听见");
DropDownList1.Items.Add("命运");
DropDownList1.Items.Add("口是心非");

}

}

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
switch (DropDownList1.SelectedIndex)
{
case 0:
Response.Write("你选择的是第一项");

代码是正确的啊,就DropDownList的AutoPostBack属性没设置成true吧

//Default.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 id="Head1" runat="server">
<title>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList ID="DropDownList1" runat="server" OnSelectedIndexChanged="DropDownLi