WPF accessing opened print dialog and close them

Question

I have a WPF application, which needs to log out user after 5 min of inactivity.

But if user open a print dialog of any page, and do not touch screen for 5 minutes, even if I log out user and clear all child elements, print dialog still stays on top of WPF form and somebody can come and continue to print what ever page user stayed.

I tried to use;

Window window = Application.Current.MainWindow;

or

FocusManager.GetFocusedElement();

but could not achieve to access to PrintDialog and close it.

Is there any way to access it and close if user did not respond to print dialog?

Answer 1

I fixed this weird problem by using

white project. http://white.codeplex.com/wikipage?title=Working%20with%20window&referringTitle=Programming%20using%20white

By using application class, I am able to access all ModalDialogs in WPF project, and close them.

  Application application = White.Core.Application.Attach(Process.GetCurrentProcess().Id);

private void dispatcherTimer_Tick(object sender, EventArgs e)
    {
        White.Core.UIItems.WindowItems.Window window = application.GetWindow("MainWindow");
        List<White.Core.UIItems.WindowItems.Window> modalWindows = window.ModalWindows();
        foreach (White.Core.UIItems.WindowItems.Window modalWindow in modalWindows)
        {
            modalWindow.Close();
        }
    }

Answer 2

You can use p/invoke for this. Use findwindow to find any window and destroywindow to close it.

https://msdn.microsoft.com/en-us/library/windows/desktop/ms633499(v=vs.85).aspx

Answer 3

If I understand correctly, you're able to do the user logout at the 5 minute mark (I presume via the timer event handler), but if the print dialog was open, then the printout can still end up happening.

The question is, what's really the important thing here, closing the dialog, or preventing the subsequent printout? Also, are you logging out the user but keeping the program going, or is the program quitting?

If the app is supposed to shut down, then your code can call the Application object's Shutdown() method, which will close any modal dialogs as part of the shutdown process.

If the app is supposed to keep running without a current user, then I would think the White library is your best bet. It's unclear why you've moved away from this.

With or without closing the print dialog, however, the printing code should check to see if the user is still logged in before it actually prints something. If the login expired while the print dialog was on screen, the printing code should simply exit without printing anything.