Having Trouble Setting Window's Owner in Parent's Constructor

Is there anything wrong in WPF with setting the Owner property of a window to its parent in that parent's constructor? There shouldn't be, right? So why am I getting an XamlParseException from the following code?

public partial class MainView : Window
{
    private readonly OwnedWindow owned;

    public MainView()
    {
        InitializeComponent();
        owned = new OwnedWindow();

        owned.DataContext = DataContext;

        var window = GetWindow(this);
        owned.Owner = this;  //Setting to window causes the same error

        ...
    }

I should clarify that removing the owned.Owner = this; also removes the runtime error.

The details of the exception:

XamlParseException was unhandled

The invocation of the constructor on type '...MainView' that matches the specified binding constraints threw an exception.

Actually, I looked at the Inner Exception, and it says:

Cannot set Owner property to a Window that has not been shown previously.

So I'm looking into that now.