Window.Activate() not working properly

Question

Sometime, Window.Activate() not working in other system.

var window = Application.Current.Windows.OfType<Window>().FirstOrDefault(y => y.IsActive) ?? Application.Current.Windows.OfType<Window>().FirstOrDefault();
if (window != null) 
    window.Activate();

I want a solution which should not fail in any system and also want to know the main cause of this.

Answer 1

It can fail if you call it from non-UI thread. In that case you should to wrap call into dispatcher.

Application.Current.Dispatcher.Invoke(() =>
{       
    ///.... UI stuff
});