纠结于到底是原创还是转载发表，考虑再三，最终还是选择以转载发表，本文参考来自于【fanfengchimo】的
http://blog.csdn.net/fanfengchimo/article/details/2078101的博客文章
及【jack86514】的http://blog.csdn.net/jack86514/article/details/1906436的博客文章。
本人的开发环境为win7+vs2010旗舰版+IE9
现文章整合后如下
1.vs2010创建web网站
2.default.aspx
<%@ Page Language="C#" EnableEventValidation="false" 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 runat="server">
<title></title>
<script type="text/javascript">
var httpRequest;
//输入编辑框失去焦点时，触发ajax加载下拉框(DropDownList)事件
function TextChanged() {
var obj = document.getElementById("txtInput");
var pra = "2";
createXMLHttpRequest();
//调用doContents函数
httpRequest.onreadystatechange = doContents;
//根据不同的PRA值来调用不同的服务端方法
httpRequest.open('GET',"request.aspx?pra=" + pra,true);
httpRequest.send(null);
}
//将ajax返回数据加载到下拉框(DropDownList)中
function doContents() {
if (httpRequest.readystate == 4) {
if (httpRequest.status == 200) {
var str = httpRequest.responseText;
AddDropDownListItem(str);
}
}
//添加数据到下拉框(DropDownList)中
function AddDropDownListItem(str) {
var objItem = str.split('@');
var obj = document.getElementById("ddlSelectList");
obj.options.length = 0;
var i;
for (i = 0; i < objItem.length; i++) {
var item = objItem[i].split(';');
if (item[0] != "" && item[1] != "") {
obj.options.add(new Option(item[0],item[1]));
}
}
obj.options.options[0].selected = true;
document.getElementById('Hidden1').value = obj.options[0].innerText;
}
}
//创建XMLHttpRequest对象
function createXMLHttpRequest() {
httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
//httpRequest = new ActiveXObject("Msxml2.XMLHTTP");
}
//将选中下拉框(DropDownList)的值赋给隐藏控件(Hidden1)
function func1() {
var itemText;
var obj = document.getElementById("ddlSelectList");
for (var i = 0; i < obj.options.length; i++)
{
if (obj.options[i].selected) {
itemText = obj.options[i].innerText;
document.getElementById('Hidden1').value = itemText;
}
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
<p>
<input id="txtInput" type="text" onblur="TextChanged();"/>
<asp:DropDownList ID="ddlSelectList" runat="server" Height="34px" Width="208px" onchange="func1();">
</asp:DropDownList>
<input id="Hidden1" type="hidden" name="Hidden1" />
</p>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
</form>
</body>
</html>
注意本页面中需要在第一行增加【EnableEventValidation="false"】,以解决页面出现【回发或回调参数无效】的问题。具体见下图
3.default.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Button1_Click(object sender,EventArgs e)
{
Response.Write(Request.Form["Hidden1"]);
}
}
4.request.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="request.aspx.cs" Inherits="request" %>
<!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>
</div>
</form>
</body>
</html>
5.request.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class request : System.Web.UI.Page
{
protected void Page_Load(object sender,EventArgs e)
{
Response.Clear();
string pra = Request.QueryString["pra"].ToString();
if (pra == "1")
{
Response.Write(GetString1());
}
else
{
Response.Write(GetString2());
}
Response.End();
}
private string GetString1()
{
return "First;1@Second;2@";
}
private string GetString2()
{
return "Third;1@Nine;2@Ten;3@";
}
}
以上代码已在上述开发环境进行测试。现记录下来，方便以后查找。目前后台(button事件)代码每次读取前台【Hidden1】隐藏控件的数值时，页面都会刷新一次，个人感觉实用性不是很好。