Question

I use Prism for a appliction and need a login dialog. For the login to be verified i need to initialize some of the application data that is loaded by Prism/MEF so i cant put it in App.xmal.cs
OnStartUp so i put the login dialog in the bootstrappers InitializeShell like this

   protected override void InitializeShell()
        {


            Application.Current.ShutdownMode = ShutdownMode.OnExplicitShutdown;

            //// Authenticate the current user and set the default principal
            LoginDialog auth = new LoginDialog();
            auth.WindowStartupLocation = WindowStartupLocation.CenterScreen;
            bool? dialogResult = auth.ShowDialog();

            // deal with the results
            if (dialogResult.HasValue && dialogResult.Value)
            {

                base.InitializeShell();
                Application.Current.ShutdownMode = ShutdownMode.OnMainWindowClose;

            }
            else
            {
                Application.Current.Shutdown(-1);
            }


#if SILVERLIGHT
            Application.Current.RootVisual = (Shell)this.Shell;            
#else
            Application.Current.MainWindow = (Shell)this.Shell;


            Application.Current.MainWindow.Show();
#endif
        }

I have a hard time assessing if there are any traps or drawback, anyone have a comment

Answer 1

Yes, I had exactly same dilemma. You have only one RootVisual and yet you have to force user to login. It’s a common scenario that’s not really addressed.

Here is what I did:

1. Code like you don’t have Login. Initialize shell and load first module. In my case first module contains security stuff.

2. When your “System” or whatever you call it module loaded – write code in Initialize() to call your login procedure, in my case this is SecurityService.

3. I used RegionPopupManager (example in StockTrader RI project bundled with PRISM) to show modal popup interaction.

4. When logged in – just hide popup and proceed loading other modules, populating regions, etc