Android：如果应用程序进程被杀死，动态注册的广播接收器将被激活

Question

As I know, statically registered (via manifest) broadcast receiver will be activated when the broadcast is fired, it doesn't require the app process is running. But what about the dynamically registered one?

Answer 1

AFAIK, You can make your Broadcast Receiver can run in background even your application is closed or destroyed or killed.

If you want to do above one , you should not be registering it via registerReceiver(). Register it in the manifest via a element instead. Then, it is available whether or not your application is running.

One more option if you want the broadcast receiver to killed or stopped whenever your application is closed or destroyed or killed.

you should call/invoke registerReceiver() method in your onCreate and You should call/invoke unregisterReceiver() in onResume() or in onpause() methods as per your need you can use this.

Answer 2

One of the differences between BroadcastReceiver that declared in AndroidManifest.xml and the one that registered with Context.registerReceiver() is that first one is instantiated by the Android system, when the second one - by the application code. When application process is terminated, all it's data (including all objects and jvm itself) is destroyed. So the only way to handle broadcast Intent for your receiver is to start new application process, instantiate new YourBroadcastReceiver and call its onReceive() method (and this is what it does for receivers, declared in manifest). But in case of receiver that was dynamically registered with registerReceiver() the system gets just some receiver instance, but not a mechanism for its creation. Furthermore, if for example your receiver class is non-static inner class then there is no reasonable way to instantiate it by the external (system) code because the system could not know, in which state the external object (and application) should be, to receiver worked properly. Also constructor could have arguments.

So if the process is terminated, your dynamically registered BroadcastReceiver will never called until you register new one in a new process.

Answer 3

As the android documentation says:

When you are defining broadcast receiver in your app manifest(Manifest-declared receivers),

The system package manager registers the receiver when the app is installed. The receiver then becomes a separate entry point into your app which means that the system can start the app and deliver the broadcast if the app is not currently running.

But when you are dynamically registering the broadcast receiver(Context-registered receivers),

Context-registered receivers receive broadcasts as long as their registering context is valid. For an example, if you register within an Activity context, you receive broadcasts as long as the activity is not destroyed. If you register with the Application context, you receive broadcasts as long as the app is running.

So your dynamically registered broadcast receiver will not be activated when your application is killed.