<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Register.aspx.cs" Inherits="CZBK.ItcastProject.WebApp._2015_6_2.Register" %> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title></title> <script src="../Js/jquery-1.7.1.js"></script> <script type="text/javascript"> //实现检查登录用户名是否存在 $(function () { //首先该元素不显示 $("#msg").css("display", "none"); //当光标移除之后,获取该元素的values值,并且判断如果不等于null传递给以下一般处理程序处理 $("#txtUserName").blur(function () { var userName = $(this).val(); if (userName != "") { $.post("CheckUserName.ashx", { "name": userName }, function (data) { $("#msg").css("display", "block"); $("#msg").text(data); //赋值 }); } else { alert("用户名不能为空!!"); } }); }); </script> </head> <body> <form id="form1" runat="server"> <div> 用户名:<input type="text" name="txtName" id="txtUserName" /><span id="msg" style="font-size:14px;color:red"></span><br /> 密码:<input type="password" name="txtPWD" /><br /> <input type="submit" value="注册" /> </div> </form> </body> </html>
对应的一般处理程序代码如下:

using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace CZBK.ItcastProject.WebApp._2015_6_2 { /// <summary> /// CheckUserName 的摘要说明 /// </summary> public class CheckUserName : IHttpHandler { public void ProcessRequest(HttpContext context) { context.Response.ContentType = "text/plain"; string userName=context.Request["name"]; BLL.UserInfoService UserInfoService = new BLL.UserInfoService(); //if (UserInfoService.GetUserInfo(userName) != null) if (userName== "1231") { context.Response.Write("此用户名已存在!!"); } else { context.Response.Write("此用户名可用!!"); } } public bool IsReusable { get { return false; } } } }