Is there a way to prevent that a WPF page was navigated away?

I'm building a WPF navigation app, with pages. I want to ask the user if he want to save the changes when he leaves a page.

Is there a way to do it?

Register for the NavigationService.Navigating event. Don't forget to remove your registration when you are done, since NavigationService sticks around basically forever.

When you get the Navigating event and there are changes, show a MessageBox to confirm with the user or give them a chance to save their data. If they hit Cancel, set e.Cancel = true to cancel the navigation.