android，如何监听通知权限变更事件

Question

on android app could open the notification permission by

Intent intent = new Intent(Settings.ACTION_APP_NOTIFICATION_SETTINGS)
        .putExtra(Settings.EXTRA_APP_PACKAGE, context.getPackageName());
startActivity(intent);

and turn it on or off.

how to listen to permission change happened here? will it be broadcasted?

EDIT: >28 seems there is broadcast, but no solution found yet for api before that. https://developer.android.com/reference/android/app/NotificationManager#ACTION_APP_BLOCK_STATE_CHANGED

ACTION_APP_BLOCK_STATE_CHANGED
Added in API level 28

public static final String ACTION_APP_BLOCK_STATE_CHANGED
Intent that is broadcast when an application is blocked or unblocked. This broadcast is only sent to the app whose block state has changed. 

Answer 1

I don't believe it is possible to be notified, but I'd love a correction if I'm wrong. That said, a user could also change this at any time, not just when you fire your Intent. While areNotificationsEnabled() will help here, unfortunately you might also need to cover the case of notification channels in newer APIs as well as notification channel groups.

Answer 2

I think it is not possible. If the user grants permission for the app, the only way that you find out is if you call checkSelfPermission() again.

If the user revokes a previously-granted permission, your process is terminated, and you would find out about the permission change by calling checkSelfPermission() the next time your app runs. So I think every time you start your app, call checkSelfPermission() to find out if there were any changes.