Question

Suppose I have a ListBox which is bound to a collection of Foo objects, and the selected Foo is displayed in a contentcontrol with the content template being a FooView.

Is there a way that I can make it so that the FooView passes the selected Foo to the constructor of the FooViewModel which is it’s datacontext via the ViewModelLocator?

Answer 1

MainViewModel

/*INotifyPropertChanged property*/
public FooViewModel CurrentFooVM{
    get{/*INPC code*/}
    private set{/*INPC code*/}
}

/*INotifyPropertChanged property*/
public Foo SelectedFoo{
    get{/*INPC code*/}
    set{/*INPC code*/ CurrentFooVM = new FooViewModel(_selectedFoo)}
}

public ObservableCollection<Foo> Foos {get; private set;}

MainView

<ListBox ItemsSource={Binding Foos}
         SelectedItem={Binding SelectedFoo}>...
<FooView... bind to CurrentFooVM...