BackgroundTaskBuilder, but the application will throw an exception if you register a task twice, so you must check if you have already registered a task.
BackgroundExecutionManager.RequestAccessAsync(), but make sure that you really have the permission. The call returns the type of access (
BackgroundAccessStatusenum) which will indicate whether you have access or not.
BackgroundAccessManager. One method to know if your app is updated, is to register another task with a
SystemTrigger, type of