Asp. NET in the use of application objects to achieve a simple online count function _ practical skills

Note: Recently in review asp.net, in order to deepen the impression, will make some small demo program, share to everyone.

1 new asp.net web site, edit the Global.asax file, the modified file as shown below.

 <%@ application language= "C #"%> <script "Server" > void runat=
  Art (object sender, EventArgs e) {//code that runs at application startup application["Currentusercount"] = 0; } void Application_End (object sender, EventArgs e) {//code that runs when the application shuts down Application_Error (obje CT sender, EventArgs e) {//code to run when an unhandled error occurs} void Session_Start (object sender, EventArgs e) {//
    Code Application.Lock () that runs when a new session starts;
    application["Currentusercount"] = (int) application["Currentusercount"] + 1;
  Application.UnLock (); 
    } void Session_End (object sender, EventArgs e) {//code that runs at the end of the session.
    Note: Session_End events are raised only if the sessionstate mode in the Web.config file is set to InProc.
    If the session mode is set to StateServer//or SQL Server, the event is not raised.
    Application.Lock ();
    application["Currentusercount"] = (int) application["Currentusercount"]-1;
  Application.UnLock (); } </script> 

2 Modify the Web.config file, add the following configuration nodes, add the configuration node bit <system.web></system.web> node below.

Copy Code code as follows:

<sessionstate mode= "InProc" timeout= "1" cookieless= "false"/>

3 Add a label to the Default.aspx file to display the current number of people online.

Copy Code code as follows:

protected void Page_Load (object sender, EventArgs e)
{
This. Label1.Text = application["Currentusercount"]. ToString ();
}

4 successively use IE and Chrome browser to access the application, to get the results shown in the following figure.