System.ArgumentNullException in RxApp static constructor

[ondrejpialek]

Hi, when you try to create a ReactiveCommand before you have a RootVisual assigned in SL, RxApp will throw an exception because it is checking InUnitTestRunner() passing in Application.Current.RootVisual which it expects been set.

To reproduce simply create a new SL project, have a ViewLocator as a static resource to which you bind from the view. When instantiating the view, the model gets instantiated first and since the view wasn't set to the RootVisual before the model was instantiated it will be null.

Workaround: in Application_Startup set RootVisual to new Grid() and then set to the main view.

[anaisbetts]

I believe this should be fixed in master. Please reopen this if it's still broken