用户在线、离线列表 (续)

最新推荐文章于 2023-08-18 08:03:55 发布

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最新推荐文章于 2023-08-18 08:03:55 发布

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分类专栏： asp.net

本文链接：https://blog.youkuaiyun.com/zhanglong_longlong/article/details/35987987

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本文介绍了一种使用单例模式实现在线用户列表的方法。通过创建一个全局唯一的在线用户实例，当用户登录或注销时更新在线状态。文章还展示了如何在网页上实时显示用户的在线状态。

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前面讲到用Cache来实现在线用户存储，今天主要改为单列模式来实现这个列表存储。

OnlineUser.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;

namespace ClassLibrary1
{
    public class OnlineUser
    {
        private Dictionary<string, string> dd = new Dictionary<string, string>();
        private static OnlineUser s_Instance = new OnlineUser();
        private object m_OnlineMembers_Locker = new object();
        /// <summary>
        /// 在线列表池的唯一实例
        /// </summary>
        public static OnlineUser Instance
        {
            get { return s_Instance; }
        }

        public void CreateOnLine()
        {
            lock (m_OnlineMembers_Locker)
            {
                if (dd.ContainsKey(HttpContext.Current.Session.SessionID))
                {
                    dd.Remove(HttpContext.Current.Session.SessionID);
                }

                dd.Add(HttpContext.Current.Session.SessionID, HttpContext.Current.User.Identity.Name);
            }
        }

        public Dictionary<string, string> GetDD()
        {
            return dd;
        }

        public void Remove(string userId)
        {
            dd.Remove(userId);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using ClassLibrary1;

namespace WebApplication8
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        private static object o = new object();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                
                if (Request.Cookies["Name"] != null && Request.Cookies["Password"] != null)
                {
                    this.txtName.Text = Request.Cookies["Name"].Value;
                    this.txtPwd.Attributes["value"] = Request.Cookies["Password"].Value;
                }
            }
        }

        protected void btnLogin_Click(object sender, EventArgs e)
        {
            if (MemberInfo.GetUserList().Contains(this.txtName.Text))
            {
                Response.Cookies["Name"].Expires = DateTime.Now.AddDays(-1);
                Response.Cookies["Password"].Expires = DateTime.Now.AddDays(-1);

                if (CheckBoxRememberMe.Checked)
                {
                    Response.Cookies["Name"].Expires = DateTime.Now.AddDays(7);
                    Response.Cookies["Password"].Expires = DateTime.Now.AddDays(7);
                }

                Response.Cookies["Name"].Value = this.txtName.Text.Trim();
                Response.Cookies["Password"].Value = this.txtPwd.Text.Trim();

                var ticket = new System.Web.Security.FormsAuthenticationTicket(1, this.txtName.Text, DateTime.Now, DateTime.Now.AddDays(1), false, "USER");
                var encryptedTicket = System.Web.Security.FormsAuthentication.Encrypt(ticket);

                if (Request.Cookies[System.Web.Security.FormsAuthentication.FormsCookieName] != null)
                    Request.Cookies.Remove(System.Web.Security.FormsAuthentication.FormsCookieName);

                var loginIdentify = new HttpCookie(System.Web.Security.FormsAuthentication.FormsCookieName);
                loginIdentify.Expires = DateTime.Now.AddDays(1);
                loginIdentify.Value = encryptedTicket;

                Response.AppendCookie(loginIdentify);

                Session.Abandon();

                if (!String.IsNullOrEmpty(Request.QueryString["ReturnUrl"]) && !Request.QueryString["ReturnUrl"].ToLower().Contains("profile"))
                    Response.Redirect(Server.UrlDecode(Request.QueryString["ReturnUrl"]));
                else
                    Response.Redirect(System.Web.Security.FormsAuthentication.DefaultUrl);

            }
        }

        public void CreateCacheOnLine()
        {
            Dictionary<string, string> DD = new Dictionary<string, string>();

            if (HttpContext.Current.Cache["cacheName"] != null)
            {
                DD = (Dictionary<string, string>)HttpContext.Current.Cache["cacheName"];
                if (DD.ContainsKey(HttpContext.Current.Session.SessionID))
                {
                    DD.Remove(HttpContext.Current.Session.SessionID);
                }
            }
            
            DD.Add(HttpContext.Current.Session.SessionID,this.txtName.Text);

            HttpContext.Current.Cache.Insert("cacheName", DD, null, DateTime.Now.AddMinutes(60), System.Web.Caching.Cache.NoSlidingExpiration);

        }

    }
}

WebForm.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm2.aspx.cs" Inherits="WebApplication8.WebForm2" %>

<!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></title>
    <script type="text/javascript" src="Scripts/jquery-1.4.1.min.js"></script>
    <script type="text/javascript">
        function OnLine() {
            $.getJSON("Handler1.ashx?" + (Math.random() + new Date().getMilliseconds()) + "", null, function (data) {
                $("#tbUserList").html("");
                var str = "<tr><td>memberName</td><td>是否在线</td></tr>";
                $.each(data.userList, function (i, item) {
                    if (item.onLine == "yes")
                        str += "<tr><td>" + item.memberName + "</td><td>在线</td></tr>";
                    else
                        str += "<tr><td>" + item.memberName + "</td><td>离线</td></tr>";
                });
                $("#tbUserList").append(str);
            })
        }
        window.setInterval(OnLine, 1000);//1000*60
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <table id="tbUserList">
    </table>

        <asp:Button ID="Button1" runat="server" Text="退出" onclick="Button1_Click" />
    </div>
    </form>
</body>
</html>

WebForm2.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using ClassLibrary1;
using System.Web.Security;

namespace WebApplication8
{
    public partial class WebForm2 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
          //  ClassLibrary1.OnlineUser.Instance.CreateOnLine();
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            FormsAuthentication.SignOut();
            Session.Abandon();
            Response.Redirect(Request.Url.ToString());
        }
    }
}

Handler1.ashx

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using ClassLibrary1;

namespace WebApplication8
{
    /// <summary>
    /// Handler1 的摘要说明
    /// </summary>
    public class Handler1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            System.Text.StringBuilder sb = new System.Text.StringBuilder();
            Dictionary<string, string> dd = OnlineUser.Instance.GetDD();
   
            sb.Append("{\"userList\":[");
            foreach(var userList in MemberInfo.GetUserList())
            {
                if (dd.ContainsValue(userList))
                    sb.Append("{\"memberName\":\""+userList+"\",\"onLine\":\"yes\"},");
                else
                    sb.Append("{\"memberName\":\"" + userList + "\",\"onLine\":\"no\"},");
            }

            sb.Remove(sb.Length-1, 1);
            sb.Append("]}");

           context.Response.Write(sb.ToString());
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

Global.asax

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.SessionState;
using ClassLibrary1;

namespace WebApplication8
{
    public class Global : System.Web.HttpApplication
    {

        protected void Application_Start(object sender, EventArgs e)
        {
        }

        protected void Session_Start(object sender, EventArgs e)
        {
            Application.Lock();

            if (HttpContext.Current.User.Identity.IsAuthenticated)
            {
                OnlineUser.Instance.CreateOnLine();
            }

            Application.UnLock();
        }

        protected void Application_BeginRequest(object sender, EventArgs e)
        {

        }

        protected void Application_AuthenticateRequest(object sender, EventArgs e)
        {

        }

        protected void Application_Error(object sender, EventArgs e)
        {

        }

        protected void Session_End(object sender, EventArgs e)
        {
              Application.Lock();

              OnlineUser.Instance.Remove(Session.SessionID);

              Application.UnLock();
        }

        protected void Application_End(object sender, EventArgs e)
        {

        }
    }
}