WPF gotcha: MessageBox.Show() inside Dispatcher.Invoke

in WPF, if you’re calling MessageBox.Show() inside a Dispatcher.Invoke call (when you’re moving back to the GUI thread from a worker thread), make sure you pass a Window object for the optional first parameter when calling MessageBox.Show (e.g. MessageBox.Show(this, "Message Here", "Title Here");). if you don’t, the message box can show up non-modal alongside your app, which is almost never your intent—