如何绑定到用户控件的父窗口IsActive属性

Question

I had my WPF control set so that it had only the following code:

  InitializeComponent();
  DataContext = model; 

However, I now run into a problem where I do not want certain actions to occur while the window is not active, so I created an IsActive flag on my ViewModel, but as my code is coming from a user control, and not a window, I cannot do this without code behind in my user control. Is this the best I can do, or is there a true MVVM approach to this

Tried this, but ran into a runtime error saying that the IsActiveProperty cannot be data bound.

 Loaded += (sender, args) =>
              {
                var parentWindow = Window.GetWindow(this);
                if (parentWindow == null)
                  return;
                var isActiveWindowBinding = new Binding {Source = model.IsActive};
                parentWindow.SetBinding(Window.IsActiveProperty, isActiveWindowBinding);
              };

So, I am not doing this:

 Loaded += (sender, args) =>
              {
                var parentWindow = Window.GetWindow(this);
                if (parentWindow == null)
                  return;
                parentWindow.Activated += (o, eventArgs) => model.IsActive = true;
                parentWindow.Deactivated += (o, eventArgs) => model.IsActive = false;
              };

The biggest problem is that I cannot get the parent window until the control loads and databinding has already been completed? Would I have to create an attached behavior, which is quite a lot of pain for a simple binding.

Answer 1

Does not binding work?

<Window IsActive="{Binding Path=IsActive, Mode=OneWayToSource}"/>

Here is meant that DataContext of the window is set.

Or if you want to use window's state in user control markup, try this binding:

PropValue="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}, Path=IsActive}"