WebForm.aspx 页面通过 AJAX 访问WebForm.aspx.cs类中的方法，获取数据
WebForm1.aspx 页面 (原生AJAX请求，写法一)
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="IsPostBack.WebForm1" %> ???<!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 src="jquery-1.11.2.js" type="text/javascript"></script> ?????<script type="text/javascript"> ?????????function btnClick() { ?????????????var xmlhttp = new XMLHttpRequest(); ?????????????if (!xmlhttp) { ?????????????????alert("创建xmlhttp对象异常"); ?????????????????return false; ?????????????} ???????????????xmlhttp.open("POST", "WebForm1.aspx", true); ?????????????xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); ???????????????xmlhttp.onreadystatechange = function () { ???????????????????if (xmlhttp.readyState == 4) { ???????????????????????if (xmlhttp.status == 200) { ???????????????????????????var str = xmlhttp.responseText; // 通过alert(str)得知 str={"Json":[{"Id":"1","UserName":"张三","Age":"25","Gender":"0"}]} ???????????????????????????//debugger; ???????????????????????????var obj = $.parseJSON(str); //将str这个字符串转换成Json对象 ??????????????????????????????var name = obj.Json[0].UserName; //obj.Json取到的是[{"Id":"1","UserName":"张三","Age":"25","Gender":"0"}] 这个数组，数组里只有一个值，即：{"Id":"1","UserName":"张三","Age":"25","Gender":"0"} ??所以obj.Json[0]的值就是{"Id":"1","UserName":"张三","Age":"25","Gender":"0"} ； 而这个{"Id":"1","UserName":"张三","Age":"25","Gender":"0"} 是一个对象，所以可以通过 .UserName来获得 "张三" 这个值 ?????????????????????????????var age = obj.Json[0].Age; ?????????????????????????????document.getElementById("name").innerHTML = name; ?????????????????????????document.getElementById("age").innerHTML = age; ???????????????????????} ?????????????????????else { ?????????????????????????alert("ajax服务器错误"); ?????????????????????} ?????????????????} ???????????????} ?????????????xmlhttp.send("id=1"); ???????????} ???????</script> ?</head> ?<body> ?????<form id="form1" runat="server"> ?????<div> ?????????<table id="t1"border="1px"> ?????????????<tr><td>姓名</td><td>年龄</td></tr> ?????????????<tr><td id="name"></td><td id="age"></td></tr> ?????????</table> ??????????<input type="button" onclick="btnClick()" ?value="提交"/> ?????</div> ?????</form> ?</body> ?</html> ?WebForm1.aspx 页面 (AJAX请求，写法二,一般情况下我们用这种)
<head runat="server"> ?????<title></title> ?????<script src="jquery-1.11.2.js" type="text/javascript"></script> ?????<script type="text/javascript"> ?????????function btnClick() { ?????????????$.ajax({ ?????????????????url: "WebForm1.aspx", ?????????????????type: "Post", ?????????????????dataType: "Text", ?//请求到服务器返回的数据类型 ?????????????????data: { "id": "2" }, ???????????????????success: function (data) { ???????????????????????var obj = $.parseJSON(data); //这个数据 ???????????????????????var name = obj.Json[0].UserName; ?????????????????????var age = obj.Json[0].Age; ???????????????????????document.getElementById("name").innerHTML = name; ?????????????????????document.getElementById("age").innerHTML = age; ?????????????????} ???????????????}) ?????????} ?????</script> ?</head> ?<body> ?????<form id="form1" runat="server"> ?????<div> ?????????<table id="t1"border="1px"> ?????????????<tr><td>姓名</td><td>年龄</td></tr> ?????????????<tr><td id="name"></td><td id="age"></td></tr> ?????????</table> ??????????<input type="button" onclick="btnClick()" ?value="提交"/> ?????</div> ?????</form> ?</body> ?</html> ?WebForm1.aspx.cs
如果你是try...catch里面使用了Response.End()的话，会被捕捉到一个异常:线程被中止" 解决方法：请点击
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; ?using System.Data; ???namespace IsPostBack ?{ ?????public partial class WebForm1 : System.Web.UI.Page ?????{ ?????????protected void Page_Load(object sender, EventArgs e) ?????????{ ?????????????string id = Request["id"]; //如果不是通过ajax 请求提交数据 就不会取到这个id ，所以此时的id 为null。但是如果是通过ajax请求提交数据，因为提交数据中有提交id，所以就能够取到这个id ，此时的id就有值了。 ???????????????if (!string.IsNullOrEmpty(id)) // 如果不是通过ajax 请求提交数据 就不会进入花括号来调用GetUserData(string id) 方法 ?????????????{ ???????????????????GetUserData(id); //如果是通过ajax请求提交数据，就会进入花括号来调用GetUserData(string id) 方法 ?????????????} ???????????????????????} ???????????void GetUserData(string id) ?????????{ ?????????????DataTable dt= SqlHelper.ExecuteDataTable("select * from T_User where id=@id", new SqlParameter("id", id)); ?????????????string data= DataTableConvertJson.DataTableToJson("Json", dt); ???????????????Response.Write(data); ?????????????Response.End(); //将当前所有缓冲的输出发送到客户端，停止该页的执行，如果没有这一步的话，程序还会往后执行，除了把data输出到客户端之外，还会将webForm1.aspx里面的html代码都输出到页面。 ?????????????????????????????????????} ?????} ?} ?WebForm.aspx 页面通过 AJAX 访问WebForm.aspx.cs类中的方法，获取数据(转)
原文地址：http://www.cnblogs.com/yellowcool/p/7497231.html