ASP.NET使用Ajax如何返回Json对象的示例方法介绍

using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;
using System.Collections.Generic;
namespace WebLogin
{
 /// <summary>
 /// $codebehindclassname$ 的摘要说明
 /// </summary>
 [WebService(Namespace = "http://tempuri.org/")]
 [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
 public class Register1 : IHttpHandler
 {
 public void ProcessRequest(HttpContext context)
 {
 context.Response.ContentType = "application/json";//设置响应内容的格式是json格式
 string id = context.Request["id"];
 string pwd = context.Request["pwd"];
 string name = context.Request["name"];
 List<string> msgList = new List<string>();
 if (String.IsNullOrEmpty(id))
 {
 msgList.Add("{\"id\":\"idMsg\",\"message\":\"用户名不能为空.\"}");
 }
 if (pwd==null || pwd=="")
 {
 msgList.Add("{\"id\":\"pwdMsg\",\"message\":\"密码不能为空.\"}");//形如：{"id":"pwdMsg","message":"密码不能为空."}
 }
 if (name==null || name=="")
 {
 msgList.Add("{\"id\":\"nameMsg\",\"message\":\"姓名不能为空.\"}");
 }
 string responseText = "";
 if (msgList.Count == 0)
 {
 //调用后台代码写入数据库
 responseText = "{\"success\":true,\"message\":\"注册成功\"}";
 }
 else
 {
 string msgsValue = "";
 for (int i = 0; i < msgList.Count; i++)
 {
 msgsValue += msgList[i] + ",";//将列表中的每一个字符串连接起来，用","隔开,不过最后还会多","
 }
 msgsValue=msgsValue.Substring(0, msgsValue.Length - 1);//去掉末尾的","
 msgsValue = "[" + msgsValue + "]";//用"[]"括起来,如:[{"id":"pwdMsg","message":"密码不能为空."},{"id":"nameMsg","message":"姓名不能为空."}]
 responseText = "{\"success\":false,\"message\":\"注册失败\",\"msgs\":" + msgsValue + "}";
 //最的形如:{"success":false,"message":"注册失败","msgs":[{"id":"pwdMsg","message":"密码不能为空."},{"id":"nameMsg","message":"姓名不能为空."}]}
 }
 context.Response.Write(responseText);
 }
 public bool IsReusable
 {
 get
 {
 return false;
 }
 }
 }
}