MetroTabControl built-in close button - how to show confirmation dialog?

[Ido00]

My TabItems have CloseButtonEnabled = true. I have CloseCommand : ICommand that I use for CloseTabCommand. Its CanExecute always returns true and the Execute function awaits on some task cancellations before preceding (I've set Execute to async void).

This seems to work fine, but I am not sure how to show the user a confirmation dialog before closing the tab and would appreciate help with that.

I use the MetroWindow.ShowMessageAsync function. I can't use it in the CanExecute function as it would require changing its signature. I can't use it in the Execute function, since as soon as it reaches the await line, execution stops and removes the tab before the user even replies to the confirmation dialog. This also makes me wonder whether my cancellation is actually awaited properly.