Converting WPF to XBAP (PRISM 2.2)

One day I had to make a conversion from WPF (PRISM 2.2) desktop application to XBAP application. Task which seems to be straightforward took me more time that I expected. I encountered some problems and I want to share all my conclusions and experiences.

My original approach in WPF desktop app (PRISM 2.2) is:

1. No StartupUri attribute in App.xaml 
2. Regions are defined in Shell.xaml e.g. cal:RegionManager.RegionName="{x:Static common:RegionNames.DocRegion}"
3. App.xaml.cs / OnStartup creates and runs UnityBootstrapper
4. UnityBootstrapper registers Modules, Types, creates ShellPresentationModel + Shell

Basically UnityBootstrapper is responsible for creating/instantiating the Shell.


WPF => XBAP conversion
Step 1.
Instead of using App.xaml.cs and

   1:     protected override void OnStartup(StartupEventArgs e) 

   2:     {

   3:        base.OnStartup(e);

   4:        UnityBootstrapper bootstrapper = new Bootstrapper();

   5:        bootstrapper.Run();

   6:     } 

 I had to use App.xaml and StartupUri="..." attribute.

Step 2.
I had to remove all my XAML region references cal:RegionManager.RegionName="..." and replace them with RegionManager.SetRegionName(..., ....). XBAP application (with StartupUri attribute) creates Shell before creating Bootstrapper, so at this stage application is not aware of existence of RegionManager.

   1:      public partial class Shell : Page, IShellView

   2:      {

   3:          public Shell()

   4:          {

   5:              Bootstrapper bootstrapper = new Bootstrapper(this);

   6:              InitializeComponent();

   7:              bootstrapper.Run();

   8:          }

   9:          

  10:          //...

  11:   

  12:      }

Step 3.
I had to populate the constructor of my Shell with Bootstrapper and pass Shell reference into Bootstrapper to make region registering process (step 2) possible.

   1:  public class Bootstrapper : UnityBootstrapper

   2:      {

   3:          private IShell shell;

   4:   

   5:          public Shell Shell

   6:          {

   7:              get { return shell as Shell; }

   8:          }

   9:   

  10:          public Bootstrapper(IShell shell)

  11:          {

  12:              shell = shell;

  13:          }

  14:   

  15:          //...

  16:   

  17:          protected override DependencyObject CreateShell()

  18:          {

  19:              ShellPresentationModel presenter = Container.Resolve<ShellPresentationModel>();

  20:              ShellView.Model = presenter;

  21:   

  22:              RegionManager.SetRegionName(ShellView.DocRegionControl,

  23:                  RegionNames.DocRegion);

  24:   

  25:              //...

  26:   

  27:              return ShellView;

  28:          }

  29:      } 

Useful links:

• http://blogs.southworks.net/dschenkelman?s=xbap
• http://blogs.southworks.net/matiasb/2009/03/11/using-cal-with-xbap-applications/