asp.net实现无刷新DropDownList联动控件
<%@ Page language="c#" Codebehind="Example.aspx.cs" AutoEventWireup="false" Inherits="Webs.other.Example" %>
<HTML>
<HEAD>
<title>Example</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
<script>
function load(state){
var drp2 = document.getElementById("DropDownList2");
for (i = drp2.length; i >= 0; i--){
drp2.options.remove(i);
}
var oHttpReq = new ActiveXObject("MSXML2.XMLHTTP");
var oDoc = new ActiveXObject("MSXML2.DOMDocument");
oHttpReq.open("POST", "getData.aspx?state="+state, false);
oHttpReq.send("");
result = oHttpReq.responseText;
oDoc.loadXML(result);
items1 = oDoc.selectNodes("//CITY/Table/Id");
items2 = oDoc.selectNodes("//CITY/Table/shiname");
var itemsLength=items1.length;
for(i=0;i<itemsLength;i++)
//将小类的类名和编号赋予DropDownList2
{
var newOption = document.createElement("OPTION");
newOption.text=items2[i].text;
newOption.value=items1[i].text;
drp2.options.add(newOption);
}
}
window.onload = function(){load('1');}
</script>
</HEAD>
<body MS_POSITIONING="FlowLayout">
<form id="Form1" method="post" runat="server">
<asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList>
<asp:DropDownList id="DropDownList2" runat="server"></asp:DropDownList>
<asp:TextBox id="TH" runat="server"></asp:TextBox>
<asp:Button id="Button1" runat="server" Text="Button"></asp:Button>
</form>
</body>
</HTML>
cs源文件:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
namespace Webs.other
{
/// <summary>
/// Example 的摘要说明。
/// </summary>
public class Example : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.TextBox TH;
protected System.Web.UI.WebControls.Button Button1;
protected System.Web.UI.WebControls.DropDownList DropDownList2;
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
if(!this.IsPostBack)
{
// 建立数据源加载第一个DropDownList，也可以默认加载第二个
SqlConnection con = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings.Get("connStr1"));
SqlDataAdapter da = new SqlDataAdapter("select Id,shengname from Province",con);
DataSet ds = new DataSet();
da.Fill(ds);
this.DropDownList1.DataSource = ds;
this.DropDownList1.DataTextField = "shengname";
this.DropDownList1.DataValueField = "Id";
this.DropDownList1.DataBind();
// 这里是绑定客户端事件，当第一个DropDownList的选项改变时激发下面的事件onchange，这个事件将调用一个客户端方法load()
this.DropDownList1.Attributes.Add("onchange","load(this.options[this.selectedIndex].value)");
}
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Button1.Click += new System.EventHandler(this.Button1_Click);
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
private void Button1_Click(object sender, System.EventArgs e)
{
TH.Text=this.Request.Form["DropDownList2"].ToString();
}
}
}
getdata源文件
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Xml;
using System.Configuration;
using System.Text;
namespace Webs.other
{
/// <summary>
/// GetData 的摘要说明。
/// </summary>
public class GetData : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
//Response.Write(Request["state"]);
int shengNo=int.Parse(Request["state"].ToString());
SqlConnection con = new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings.Get("connStr1"));
SqlDataAdapter da = new SqlDataAdapter("select Id,shiname from City where Shengid='"+shengNo+"'",con);
DataSet ds = new DataSet("CITY");
da.Fill(ds);
XmlTextWriter writer = new XmlTextWriter(Response.OutputStream,Encoding.UTF8);
writer.Formatting = Formatting.Indented;
writer.Indentation = 4;
writer.IndentChar = ' ';
writer.WriteStartDocument();
ds.WriteXml(writer);
writer.Flush();
Response.End();
writer.Close();
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}