.net中ajax实现检测用户名的完整测子

文件列表：
1.Register.aspx
2.CheckUsername.aspx
3.CheckNickname.aspx

在Register.aspx中增加以下行：

    <script type="text/javascript" src="../JS/prototype.js" language="javascript"></script>
    <script type="text/javascript" src="../JS/ClassBackObject.js" language="javascript"></script>
    <script language="javascript" type="text/javascript">
    function createRequest(type)
    {
        var name,cbo,urlText;
        if(type=="username"){
            name = escape(document.getElementById("Username").value);
            urlText = "../Ajax/CheckUsername.aspx?username=" + name;
        }
        else
        {
            name = escape(document.getElementById("Nickname").value);
            urlText = "../Ajax/CheckNickname.aspx?nickname=" + name;
        }
        cbo = new CallBackObject();
        cbo.OnComplete = Cbo_Complete;
        cbo.OnError = Cbo_Error;
        cbo.DoCallBack(urlText);
    }
    
    function Cbo_Complete(responseText, responseXML)
    {     
         
        // 取得XML文档的根 
        var root = responseXML.documentElement; 
        var strOK
        try 
        { 
            // 取得<info>结果 
            var info = root.getElementsByTagName('value'); 
            var type = root.getElementsByTagName('type'); 
            
            // 显示返回结果 
            if(info[0].firstChild.data == "0"){
                strOK = "可以注册"
            }
            else
            {
                strOK = "不能注册"
            }
            
            if(type[0].firstChild.data == "username"){
                 $("userNameDIV").innerHTML = strOK;
             }
             else
             {
                $("nickNameDIV").innerHTML = strOK;
             }

        }catch(exception) 
        { 

        } 
    }
    
    function Cbo_Error(status, statusText, responseText)
    {
        //alert(responseText);
    }
    </script>

CheckUsername.aspx代码：

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class Ajax_CheckUsername : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //此处放置用户代码以初始化页面
        string strRes;
        string sqlcmd;
        string strName;
        int ok;
        strName = HttpContext.Current.Request.QueryString["username"];
        sqlcmd = "select count(*) from UserInfo where Username=@Username";
        SqlParameter[] param = {
            new SqlParameter("@Username",strName),
        };
        ok = Convert.ToInt32(userSql.db.ExecuteScalar(sqlcmd, param));

        if (ok > 0)
        {

            strRes = ok.ToString();
        }
        else
        {
            strRes = ok.ToString();
        }

        strRes = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><re><type>username</type><value>" + strRes + "</value></re>";
        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.ContentType = "text/xml";
        HttpContext.Current.Response.Write(strRes);
        HttpContext.Current.Response.Flush();
        HttpContext.Current.Response.End();
    }
}

CheckNickname.aspx代码：

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class Ajax_CheckUsername : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //此处放置用户代码以初始化页面
        string strRes;
        string sqlcmd;
        string strName;
        int ok;
        strName = HttpContext.Current.Request.QueryString["username"];
        sqlcmd = "select count(*) from UserInfo where Username=@Username";
        SqlParameter[] param = {
            new SqlParameter("@Username",strName),
        };
        ok = Convert.ToInt32(userSql.db.ExecuteScalar(sqlcmd, param));

        if (ok > 0)
        {

            strRes = ok.ToString();
        }
        else
        {
            strRes = ok.ToString();
        }

        strRes = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><re><type>username</type><value>" + strRes + "</value></re>";
        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.ContentType = "text/xml";
        HttpContext.Current.Response.Write(strRes);
        HttpContext.Current.Response.Flush();
        HttpContext.Current.Response.End();
    }
}

ClassBackObject.js

// JScript 文件
function CallBackObject()
{
    this.XmlHttp = this.GetHttpObject();
}

CallBackObject.prototype.GetHttpObject = function()
{
    var xmlhttp;
    /**//*@cc_on
    @if (@_jscript_version >= 5)
    try{
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP")
    }
    catch (e){
        try{
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch (E){
            xmlhttp = false;
        }
    }
    @else
    xmlhttp = false;
    @end @*/
    if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
        try{
            xmlhttp = new XMLHttpRequest();
        } catch (e){
            xmlhttp = false;
        }
    }
    return xmlhttp;
}

CallBackObject.prototype.DoCallBack = function(URL)
{
    if (this.XmlHttp){
        if(this.XmlHttp.readyState == 4 || this.XmlHttp.readyState == 0){
            var oThis = this;
            this.XmlHttp.open('POST',URL);
            this.XmlHttp.onreadystatechange = function(){oThis.ReadyStateChange();};
            //this.XmlHttp.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
            this.XmlHttp.send(null);
        }
    }
}

CallBackObject.prototype.AbortCallBack= function()
{
    if(this.XmlHttp)
        this.XmlHttp.abort();
}

CallBackObject.prototype.OnLoading = function()
{
    // Loading
}

CallBackObject.prototype.OnLoaded = function()
{
    // Loaded
}

CallBackObject.prototype.OnInteractive = function()
{
    // Interactive
}

CallBackObject.prototype.OnComplete = function()
{
    // Complete
}

CallBackObject.prototype.OnAbort = function()
{
    // Abort
}

CallBackObject.prototype.OnError = function()
{
    // Error
}

CallBackObject.prototype.ReadyStateChange = function()
{
    if (this.XmlHttp.readyState == 1)
    {
        this.OnLoading();
    }
    else if(this.XmlHttp.readyState == 2)
    {
        this.OnLoaded();
    }
    else if(this.XmlHttp.readyState == 3)
    {
        this.OnInteractive();
    }
    else if(this.XmlHttp.readyState == 4)
    {
        if(this.XmlHttp.status == 0)
            this.OnAort();
        else if(this.XmlHttp.status == 200 && this.XmlHttp.statusText == "OK")
            this.OnComplete(this.XmlHttp.responseText, this.XmlHttp.responseXML);
        else
            this.OnError(this.XmlHttp.status, this.XmlHttp.statusText, this.XmlHttp.responseText);
    }
}

另外还有prototype.js 1.5