Wiring an Event to the Red X on a WindowStyle.ToolWindow

Question

I have a UserControl that I am showing with the ShowDialog method of the WindowManager. The User Control has two buttons (Ok, Cancel) as well as some input.

I would like to also run some code when the User selects the red X in the upper right of the Window. Is there a way to wire an event to that with Caliburn Micro?

Thanks

Chuck

Answer 1

I've done something similar with the ShowWindowmethod from the WindowManager, the ShowDialog method should work in the same way when you're passing a ViewModel (which I'm assuming you're doing in this case).

It's worth reading this page in the documentation for a more complete explanation, but essentially a Screen has a CanClose method, which you can override with custom behaviour.

CanClose – The default implementation always allows closing. Override this method to add custom guard logic.

So, within the ViewModel class that you're passing to ShowDialog, you could do something like:

public override void CanClose(Action<bool> callback)
{
    bool canClose = false;

    // if (yourConditionHere)
        canClose = true;

    callback(closeDialog);
}

Where canClose could just as easily be a private field updated elsewhere in the class.