Lifecycle of Windows Phone Applications

Running 

The app launch enters the running state and will remain there until the app gets



closed by the user by pressing the back button or Task Switcher.

It is deactivated when the application chooses a camera, lock screen and so on.

It is deactivated if another application is opened.

Dormant

The app is still in memory and may be quickly restarted. The user can return it to dormant using the back button.

Tombstoned

The OS will suspend your app if it loses focus. A suspended app may be tombstoned. If the operating system becomes short of memory it will discard the cached state of the oldest dormant application. This process is called “Tombstoning”.

The events are already wired up in the App.xaml file and the event handler methods are in the App.xaml.cs file. Initially lifecycle event methods are empty and looks like the following.