ASP.NET 限制用户重复登录

 

 

实现方式，用户登录的时候记录用Session他的ID和登录时间。然后写入一个XML文件。以他的用户名命名，内容写入他的登录时间。登录后每个页面每20秒用Session的登录时间去比对写入的文件。如果正确则不用理会 如果不正确则被被踢出。因为写入的文件如果不是同一用户名登录的话是不会更新的。

代码可以实现 用户单一登录 单点登录 无限人次登录 。稍微修改就可以实现了。

login 页面

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="login.aspx.cs" Inherits="login" %>

<!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>

</head>

<body>

    <form id="form1" runat="server">

    <div>

        &nbsp;<div>

            <asp:TextBox ID="txtUser" runat="server"></asp:TextBox>

            <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="login" /><br />

          </div>

   

    </div>

    </form>

</body>

</html>

login 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;

public partial class login : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

    }

     protected void Button1_Click(object sender, EventArgs e)

        {

            string strUserId = txtUser.Text;

            string times = DateTime.Now.ToString("yyyyMMddHHmmss");

            string body = CourseXMLFileHeader + "<userTime>" + times + "</userTime></NewDataSet>";

            string CourseFilePath =Server.MapPath(".") + "file://userlist//" + strUserId + ".XML";

            if (!System.IO.File.Exists(CourseFilePath))

            {

                System.IO.FileStream NewText = System.IO.File.Create(CourseFilePath);

                NewText.Close();

                Session["SESSION_USERTIME"] = times;

                Session["SESSION_USERName"] = strUserId;

              

               

            }

            else

            {

                System.IO.File.Delete(CourseFilePath);

                System.IO.FileStream NewText = System.IO.File.Create(CourseFilePath);

                NewText.Close();

                Session["SESSION_USERTIME"] = times;

                Session["SESSION_USERName"] = strUserId;

            }

            System.IO.StreamWriter sw = new System.IO.StreamWriter(CourseFilePath, true);

            body = body.Replace("\'", "\"");

            sw.WriteLine(body);

            sw.Close();

          

            Response.Redirect("Default.aspx");

        }

    public String CourseXMLFileHeader = @"<?xml version='1.0' standalone='yes'?><NewDataSet>";

     

     

}

default 页面

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!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 id="Head1" runat="server">

    <title></title>

  

</head>

<body>

    <form id="form1" runat="server">

        <asp:GridView ID="DataList1" runat="server">

        </asp:GridView>

    </form>

</body>

</html>

<script type="text/javascript">

var x=0;

function myRefresh()

{

xRequest();

var result = "";

　　       

　          xmlHttp.open("Post", "test.aspx", false);

　　        xmlHttp.send("");

　　        result = xmlHttp.responseText;

　　        if(result!="ok")

           {

                alert("sorry,您的账号在别处登录");

                location.href='logost.aspx';

           }

          

           x++;

if(x<20)

{

setTimeout("myRefresh()",20*1000);

}

}

myRefresh();

          

var xmlHttp;

function xRequest(){

if(window.XMLHttpRequest){

   xmlHttp = new XMLHttpRequest(); //火狐浏览器。

}

else if(window.ActiveXObject){

   xmlHttp = new ActiveXObject("Msxml2.XMLHTTP"); //IE浏览器。

   if(!xmlHttp){xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");}

}

}

          

</script>

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.IO;

public partial class _Default : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        DirectoryInfo di = new DirectoryInfo(Server.MapPath(".") + "file://userlist//");

        FileSystemInfo[] dis = di.GetFileSystemInfos();

        if (dis.Length < 1)

        {

            Response.Write("<script>alert(\"目录是空的\");</script>");

        }

        else

        {

            foreach (FileSystemInfo fitemp in dis)

            {

                Response.Write(fitemp.Name + "<br>");

            }

        }

    }

}

Test.aspx 这个页面是用来检查是否被顶 只要写代码就可以了

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.IO;

using System.Xml;

public partial class test : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        string times = Session["SESSION_USERTIME"].ToString();

       string userid= Session["SESSION_USERName"].ToString();

       string CourseFilePath = Server.MapPath(".") + "file://userlist//" + userid + ".XML";

       if (times.Equals(ReadXmlReturnNode(CourseFilePath, "userTime")))

       {

           this.Response.Write("ok");

           this.Response.End();

       }

       else

       {

           this.Response.Write("no");

           this.Response.End();

       }

       

    }

    public static string ReadXmlReturnNode(string XmlPath, string Node)

    {

        XmlDocument docXml = new XmlDocument();

        docXml.Load(@XmlPath);

        XmlNodeList xn = docXml.GetElementsByTagName(Node);

        return xn.Item(0).InnerText.ToString();

    }

}

退出界面 logost .aspx

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;

public partial class logost : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        Session.Remove("SESSION_USERTIME");

        Session.Remove("SESSION_USERName");

        Response.Redirect("login.aspx");

    }

}

posted on 2009-10-20 14:13  sweting  阅读(1640)  评论(0)  编辑  收藏  举报
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