Windows Phone 8 had the ability for your app to prevent the phone from going to the lock screen: PhoneApplicationService.Current.ApplicationIdleMode = IdleDetectionMode.Disabled ;
Anybody know what the equivalent is for Universal Window Platform?
You can use this:
var displayRequest = new Windows.System.Display.DisplayRequest();
displayRequest.RequestActive();
But be aware of the fact that you are just requesting the screen to stay active. This can not prevent the user from locking the screen by himself manually.