Use Application and Session to count online people

In the Global.asax global variable file, modify the Session_Start and Session_End methods; the code is as follows:

        protected void Session_Start(object sender, EventArgs e)

        {

            //  

            Session.Timeout = 5; // Session ， 

            Application.Lock();

            Application["OnlineCount"] = Convert.ToInt32(Application["OnlineCount"]) + 1;

            Application.UnLock();

        }

        protected void Session_End(object sender, EventArgs e)

        {

            //  。

            //  :   Web.config   sessionstate  InProc  ，  Session_End  。
　　　　　　　//   StateServer  SQLServer， 。

            Application.Lock();

            Application["OnlineCount"] = Convert.ToInt32(Application["OnlineCount"]) - 1;

            Application.UnLock();



        }

This can be called on the .aspx page;

<asp:Label ID="labOnlineCount" runat="server"> &nbsp;<font color=red><%=Application["OnlineCount"]%></font>&nbsp; </asp:Label>