WPF MVVM: How to close a window

Question

I have a Button that closes my window when it\'s clicked:

Ok

Answer 1

For small apps, I use my own Application Controller for showing, closing and disposing windows and DataContexts. It's a central point in UI of an application.

It's something like this:

//It is singleton, I will just post 2 methods and their invocations
public void ShowNewWindow(Window window, object dataContext = null, bool dialog = true)
{
    window.DataContext = dataContext;
    addToWindowRegistry(dataContext, window);

    if (dialog)
        window.ShowDialog();
    else
        window.Show();

}

public void CloseWindow(object dataContextSender)
{
    var correspondingWindows = windowRegistry.Where(c => c.DataContext.Equals(dataContextSender)).ToList();
    foreach (var pair in correspondingWindows)
    {
        pair.Window.Close();              
    }
}

and their invocations from ViewModels:

// Show new Window with DataContext
ApplicationController.Instance.ShowNewWindow(
                new ClientCardsWindow(),
                new ClientCardsVM(),
                false);

// Close Current Window from viewModel
ApplicationController.Instance.CloseWindow(this);

Of course you can find some restrictions in my solution. Again: I use it for small projects, and it's enough. If you're interested, I can post full code here or somewhere else/