Multiwindow behaviour and dispatcher in WPF - wpf

Question

I have app with 2 windows.
1st LoginWindow used to authentificate user and launch main app. I use thread and run dispatcher for that:
private bool EndTrigger = false;
/.../
Thread thread = new Thread(() =>
{
MainWindow T_window = new MainWindow(t_data);
T_window.WindowState = WindowState.Maximized;
T_window.Show();
EndTrigger = true;
System.Windows.Threading.Dispatcher.Run();
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();
After that LoginWindow is closed. I used function that checks if MainWindow is ready and Timer like this:
Timer LoginWinClose = new Timer(new TimerCallback(IfLoginWinCanBeClosed), null, 2000, 1000);
and
public void IfLoginWinCanBeClosed(Object stateInfo)
{
if (EndTrigger)
{
this.Dispatcher.Invoke(new Action(delegate
{
this.Close();
}));
}
}
It works as it should: LoginWindow disapper, MainWidow appear and everything works.
But when I tryed to create one more window in MainWindow I get Exception that tells me: Application is shutting down.
It looks like closing LoginWindow leads to attemp of closing application, but if I close any other window (for example MainWindow), I still can create one more from LoginWondow without any error.
Currently I solve this by by changing
this.Close();
to
this.Visibility = Visibility.Collapsed;
It means that LoginWindow will continue to run all the time. If there any another solution?

Answer 1

Thanks to #Sham I understand where is the mistake!
Code, where new window is created located in separate thread (this is because login check operations run in the separated thread to avoid hanging LoginWindow), so I Create and run new window with separate dispatcher in that Thread, instead of main UI thread.
So, the solution is quite easy. Just need to make a little modification:
Thread thread = new Thread(() =>
{
this.Dispatcher.Invoke(new Action(delegate
{
AdminWindow T_window = new AdminWindow(t_data);
T_window.WindowState = WindowState.Maximized;
T_window.Show();
t_data.Link_auth_win.EndTrigger = true;
System.Windows.Threading.Dispatcher.Run();
}));
});
thread.SetApartmentState(ApartmentState.STA);
thread.Start();