Getting number of active sessions (online users counter) with ASP.NET

All that have to be done is in global.asax file:

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)

Application(

"OnlineUsers") = 0

End Sub

Sub Application_End(ByVal sender As Object, ByVal e As EventArgs)

End Sub

Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)

End Sub

Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)

Application.Lock()

Application("OnlineUsers") = CInt(Application("OnlineUsers")) + 1

Application.UnLock()

End Sub

Sub Session_End(ByVal sender As Object, ByVal e As EventArgs)

Application.Lock()

Application("OnlineUsers") = CInt(Application("OnlineUsers")) - 1

Application.UnLock()

End Sub

And to get the counter value in any form you want just call Response.Write(Application("OnlineUsers")) or Label1.Text = Application("OnlineUsers") whatever you feel comfortable.

It will show all open sessions.

Application.Lock() is used to lock down the application state values for editing only from one person at a time and Application.UnLock() is unlocking the state for edit from somebody else.

Hope it helps