WPF (MVVM): Closing a view from Viewmodel?
Anybody come across a clever way of closing a view in a viewmodel using MVVM?
Maybe there is a way of using binding to signal the view (window) to close?
I would really appreciate any input anyone has.
Basically i have a loginView that is bound to a loginViewModel, in the viewmodel (using binding on a command) i test to see if the login is successful and if it is i basically load up a new View (mainview) and attach its datacontext...
but i still have the loginView shown - so i need to signal it to unload..
I was also hoping for a generic solution because i am sure that i am going to need to do this sort of thing in other situations
Any ideas?
Answer
Edit: See my blog post for a more detailed explanation.
When I need to achieve that, I use a IRequestCloseViewModel interface that I created.
This interface contains only one event: RequestClose. This event is raised by the ViewModel (which inherits from a ViewModelBase class AND implement IRequestCloseViewModel) when it wants to close its associated view.
In my app, all Window inherit from an abstract class ApplicationWindow. This abstract class is notified each time the DataContext changed and in the handler checks if the DataContext support the IRequestCloseViewModel. If this is the case, an event handler is set up to close the Window when the event is fired.
Alternatively, like Kent said, you can use screen controller that handle this mecanism in an external class.