Long running task was cancelled by iOS after lock the screen

[wml2017]

On my iPhone 6+ with iOS 12, the sample works well with debug model. But when start the app on my iPhone, start LongRunning task and lock iPhone or press iPhone's home button, the background task will be cancelled automatically after 3 minutes even though check Background model, Background fetch, Background processing on Info.plist page. Could you update your sample code to fix this issue?

[shernandezp]

The implementation of OnExpiration method should be
void OnExpiration()
{
UIApplication.SharedApplication.EndBackgroundTask(_taskId);
}