AJAX+C# 验证用户是否被注册
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="AJAX.aspx.cs" Inherits="ToImage" %>
<!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>无标题页</title> <script type="text/javascript">
var httprequest=false; function sendRequest(url)
{
if(window.XMLHttpRequest) { httprequest=new XMLHttpRequest(); if(httprequest.overrideMimeType) { httprequest.overrideMimeType("text/xml");
} } else if(window.ActiveXObject) { try { httprequest=new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try { httprequest=new ActiveXObject("Microsoft.XMLHTTP"); } catch(e){} } } if(!httprequest) { window.alert("不能创建XMLHttpRequest对象实例"); return false; } httprequest.onreadystatechange=processRequest; httprequest.open("GET",url,true) httprequest.send(null); } function processRequest() { var divcheck=document.getElementById("checkinfo"); if(httprequest.readyState==4) { if(httprequest.status==200) { if(httprequest.responseXML.text=="True") { divcheck.style.color='blue'; divcheck.innerText="该用户名未被使用过，可以继续"; } else if(httprequest.responseXML.text=="False") { divcheck.style.color='red'; divcheck.innerText="该用户名以被注册过，请换一个用户名"; } else { divcheck.innerText="error!"; } } else { divcheck.innerText="error!"; } } } function userCheck(url) { var f=document.form1; var username=f.Username.value; if(username=="") { var divcheck=document.getElementById("checkinfo"); divcheck.style.color='red' divcheck.innerText="用户名不能为空"; f.Username.focus(); return false; } else { url+=f.Username.value; sendRequest(url); return false; } }
</script></head><body> <form id="form1" runat="server"> <div> <br /> <br /> <br /> <table style="width: 398px; height: 53px"> <tr> <td style="width: 67px; height: 8px; text-align: center;"> 用户名：</td> <td style="width: 13px; height: 8px; text-align: center;"> <asp:TextBox ID="Username" runat="server"></asp:TextBox> </td> <td style="width: 55px; height: 8px;"> <asp:LinkButton ID="LinkButton1" runat="server" Width="147px" >检查用户名的唯一性</asp:LinkButton> <div id="checkinfo" style="width: 138px; position: static; height: 35px; left: 31px; top: 171px;" /> </td> </tr> </table> </div> </form></body></html>public partial class AJAX : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { string url = Request.Url.ToString(); url = url.Substring(0, url.LastIndexOf('/') + 1) + "CheckUser.aspx?CheckUser="; LinkButton1.Attributes.Add("onClick", "return userCheck('"+url+"');"); }}public partial class CheckUser : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { string NewUser= Request.QueryString["CheckUser"].ToString(); bool send= IsUser(NewUser); Page.Response.ContentType = "text/xml"; Response.Write("<IsUser>"+send+"</IsUser>"); Response.End(); }private bool IsUser(newuser){ //
//读取数据库或数据源判断用户名是否存在 //}