Popping a MessageBox for the main app with Backgroundworker in WPF

Question

In a WPF app, I am using a BackgroundWorker to periodically check for a condition on the server. While that works fine, I want to pop a MessageBox notifing the users if some

Answer 1

Replace

MessageBox.Show("I should block the main window"); 

with

this.Invoke((Func)(() => MessageBox.Show("I should block the main window")));

that will cause the message box to be on the main thread and will block all access to the UI until it gets a response. As a added bonus this.Invoke will return a object that can be cast in to the DialogResult.