AJAX实现DropDownList无刷新二级联动(转载)

 

前台代码:

<%@ Page Language="C#" CodeFile="DropDownListDemo.aspx.cs" Inherits="DropDownListDemo" %>

<!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:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <asp:DropDownList ID="DropDownList1" runat="server" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"></asp:DropDownList>
                <asp:DropDownList ID="DropDownList2" runat="server"></asp:DropDownList>
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>
    </form>
</body>
</html>

 

后台代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;

public partial class DropDownListDemo : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        DropDownList1.AutoPostBack = true;
        DropDownList2.AutoPostBack = true;
        if (!IsPostBack)
        {
            DropDownList1.Items.Add("----请选择----");
            DropDownList2.Items.Add("----请选择----");
            BindDDL("SELECT 列名1,列名2 FROM 表名", DropDownList1);
            DropDownList2.Enabled = false;
        }
        else if (DropDownList1.SelectedIndex == 0)
        {
            DropDownList2.Enabled = false;
        }
    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList2.Items.Clear();
        DropDownList2.Items.Add("----请选择----");
        if (DropDownList1.SelectedIndex == 0)
        {
            DropDownList2.Enabled = false;
        }
        else
        {
            DropDownList2.Enabled = true;
            BindDDL("SELECT 列名1,列名2 FROM 表名 WHERE 条件1 = '" + DropDownList1.SelectedValue + "'", DropDownList2);
        }
    }
    protected void BindDDL(string queryString, DropDownList ddl)
    {
        string connectionString = "Data Source=****;Initial Catalog=****;User ID=****;Password=****";
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlCommand command = new SqlCommand(queryString, connection);
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();
            while (reader.Read())
            {
                ddl.Items.Add(new ListItem(reader[0].ToString(), reader[1].ToString()));
            }
            reader.Close();
        }
    }
}

 

 

原文地址:http://blog.sina.com.cn/s/blog_3d9600900100pg1i.html

再次感谢作者的分享。

posted on 2014-04-16 13:35  bin790302901  阅读(989)  评论(0编辑  收藏  举报