Service (在Service中注册BroadcastReceiver)

注册广播接收者的服务类

public class MyService extends Service {

    private ScreenReceiver receiver;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        // 1 创建ScreenReceiver对象
        receiver = new ScreenReceiver();
        // 2 创建intentfilter对象,并指定接收什么广播
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_SCREEN_ON);
        // 3 注册广播接收者
        registerReceiver(receiver, filter);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        // 4 解除广播接收者注册
        unregisterReceiver(receiver);
    }
}

广播接收者

public class ScreenReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if(Intent.ACTION_SCREEN_OFF.equals(action)){
            System.out.println("关闭");
        }
        else if(Intent.ACTION_SCREEN_ON.equals(action)){
            System.out.println("开启");
        }
    }

}

Activity中启动服务

public class MainActivity extends Activity {

    private Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 隐式启动服务
        intent = new Intent(this, MyService.class);
    }

    public void click1(View v) {
        startService(intent);
    }

    public void click3(View v) {
        stopService(intent);
    }

}