I am implementing an app where an alarm comes at a time specified by the user. I implemented a method of generating a notification at a fixed time using AlarmManager, and also implemented a method of generating a periodic notification through a stable background using WorkManager.
@Problem
All of the methods I tried above triggered a periodic alarm only when the app was alive on the task... If you exit the app by pressing onBackPressed(), it works, but the alarm itself does not work from the moment the task is blown. Google docs recommends using FCM, but this seemed to require a server for the alarm to sound at the user-specified time, and similarly, the notification was triggered only when the app was alive on the task. Since Android Oreo, background regulation has become severe, and I have been struggling with this problem for almost a month. please.
@Question
Regardless of the Android version, even if the task launches the app, can you know the code for the app that sounds the alarm at the time specified by the user?