使用 WCF 服务的 WPF 应用程序的会话超时

Question

Need help for WPF application..

The application uses WCF service to allow user to log in and do other database transactions. The client wants the application to log out the user if there is a session time out.

Was able to add a function on the forms load event to check if the user is logged in and display the timeout message and log out the user.

Have created a base class for the forms and have a overridable Onload event of the form, using this event I am able to have all the forms checked if the user is logged in.

Problem :

When the user is on a form and when there is a session timeout when the user is on the form. When the user clicks on a button or a drop down which would trigger a call to the WCF service the application would give error as the session has timeout.

I would either have to validate if the user is logged in on every function and control event that would call the WCF service.

Is there a way like similar to the web page load event which is always being called on every event on the page using which we can have the application check if the user is logged in or not.

Your help on this would be of great help

Answer 1

You can listen to all the RoutedEvents like below. But this will called for all the events (I mean ALL the events) so you can put the check on the particular RoutedEvents like Button.ClickEvent or ComboBox.SelectionChanged

    public MainWindow()
    {
        InitializeComponent();
        RoutedEvent[] events = EventManager.GetRoutedEvents();

        if(events!=null)
        {
           foreach (RoutedEvent e in events)
            AddHandler(e, new RoutedEventHandler(GenericHandler),true);
         }

    }

    private void GenericHandler(object sender, RoutedEventArgs routedEventArgs)
    {
         if (routedEventArgs.RoutedEvent == ButtonBase.ClickEvent || 
            routedEventArgs.RoutedEvent == Selector.SelectionChangedEvent)
        {
            //Here you can check for if user is logged on or not. 
        }

    }