<%@ Page Language="C#" AutoEventWireup="true" CodeFile="listbox.aspx.cs" Inherits="test_listbox" %>
<!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>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ListBox ID="ListBox1" runat="server" AutoPostBack="True" Height="129px" OnSelectedIndexChanged="ListBox1_SelectedIndexChanged"
SelectionMode="Multiple" Width="103px">
<asp:ListItem>苹果</asp:ListItem>
<asp:ListItem>柿子</asp:ListItem>
</asp:ListBox><br />
<br />
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br />
<br />
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="添加" />
<br />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label><br />
<br />
<br />
＝＝＝＝＝＝＝＝＝＝＝＝＝＝<br />
<asp:Label ID="Label2" runat="server" Text="省" Width="26px"></asp:Label>
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
</asp:DropDownList><br />
<asp:Label ID="Label3" runat="server" Text="市" Width="27px"></asp:Label><asp:DropDownList
ID="DropDownList2" runat="server">
</asp:DropDownList><br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
</div>
</form>
</body>
</html>
======================================================
using System;
using System.Data;
using System.Configuration;
using System.Collections;
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.Data.SqlClient;
public partial class test_listbox : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
SqlConnection con = DB2.createConnection();
con.Open();
SqlCommand cmd = new SqlCommand("select * from province", con);
SqlDataReader sdr = cmd.ExecuteReader();
this.DropDownList1.DataSource = sdr;
this.DropDownList1.DataTextField = "proName";
this.DropDownList1.DataValueField = "proID";
this.DropDownList1.DataBind();
sdr.Close();
//con.Close();
SqlCommand cmdCity =new SqlCommand("select * from city where proID=" + this.DropDownList1.SelectedValue.ToString(),con);
sdr = cmdCity.ExecuteReader();
this.DropDownList2.DataSource = sdr;
this.DropDownList2.DataValueField = "cityID";
this.DropDownList2.DataTextField = "cityName";
this.DropDownList2.DataBind();
sdr.Close();
con.Close();
}
}
protected void Button1_Click(object sender, EventArgs e)
{
this.ListBox1.Items.Add(this.TextBox1.Text);
}
protected void ListBox1_SelectedIndexChanged(object sender, EventArgs e)
{
Label1.Text = "你已经选择了：" + this.ListBox1.SelectedItem.Text;
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
SqlConnection con = DB2.createConnection();
con.Open();
SqlCommand cmd = new SqlCommand("select * from city where proID=" + this.DropDownList1.SelectedValue.ToString(), con);
SqlDataReader sdr = cmd.ExecuteReader();
this.DropDownList2.DataSource = sdr;
this.DropDownList2.DataValueField = "cityID";
this.DropDownList2.DataTextField = "cityName";
this.DropDownList2.DataBind();
sdr.Close();
con.Close();
}
}
下面一节课是: DropDownList 与 ListBox 的联动！