Service

Service生命周期

知识点:
Service中的onBind方法,返回IBinder接口,如果直接实现,方法数太多,因此返回自定义MyBinder继承Binder类

@Override
public IBinder onBind(Intent intent) {
    return new IBinder() {
        @Override
        public String getInterfaceDescriptor() throws RemoteException {
            return null;
        }
        @Override
        public boolean pingBinder() {
            return false;
        }
        @Override
        public boolean isBinderAlive() {
            return false;
        }

合理的写法

@Override
public IBinder onBind(Intent intent) {
    Log.i("zhang","服务 onBind");
    return new MyBinder();
}
public class MyBinder extends Binder {
    //自定义方法
    //比如 我要获取这个service
    public MyService getService() {
        return MyService.this;
    }
}

绑定服务会随着Activity结束而结束,启动服务则不受activity影响

MainActivity

    private ServiceConnection mConnection=new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.i("zhang","服务 mConnection onServiceConnected");
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.i("zhang","服务 mConnection disConnected");
        }
    };

    @butterknife.OnClick({R.id.start, R.id.stop, R.id.bind, R.id.unbind})
    public void onViewClicked(View view) {
        switch (view.getId()) {
            case R.id.start:
                Intent intent = new Intent(MainActivity.this, MyService.class);
                startService(intent);
                break;
            case R.id.stop:
                stopService(new Intent(MainActivity.this, MyService.class));
                break;
            case R.id.bind:
                Intent bindintent = new Intent(MainActivity.this, MyService.class);
                bindService(bindintent,mConnection,BIND_AUTO_CREATE);
                break;
            case R.id.unbind:
                unbindService(mConnection);
                break;
        }
    }

MyService

    @Override
    public IBinder onBind(Intent intent) {
        Log.i("zhang","服务 onBind");
        return new MyBinder();
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("zhang","服务 onCreate");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("zhang","服务 onStartCommand");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("zhang","服务 onDestroy");
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("zhang","服务 onUnbind");
        return super.onUnbind(intent);
    }

    public class MyBinder extends Binder {
        //自定义方法
        //比如 我要获取这个service
        public MyService getService() {
            return MyService.this;
        }
    }

AndroidManifest

运行

1. start -> stop

说明启动service,一定会调用onStartCommand方法

2. start -> start

重复启动service,只会调用一次onCreate方法,onStartCommand可多次调用

3. bind -> unbind

bind也能创建service,执行onCreate方法

4. bind -> start

bind之后start service,不会重新onCreate,只会执行onStartCommond

5. bind -> start -> stop

6. bind -> start -> unbind

bind创建的Service,start之后,unbind只能解绑,不能销毁

7.bind -> start -> unbind ->stop

同上5,6,7对比,说明bind创建的Service,start之后,如果要销毁service,必须先unbind,然后stop,才能销毁

8. bind -> bind

重复bind并未执行任何方法

9. bind -> start ->unbind ->bind

若要执行ServiceConnection的方法,必须先unbind,然后bind调用
即可获得值service中的值,达到实时监控service中的值方法

10. bind -> 点击返回键

activity销毁之后,bind的service也unbind,销毁

11. bind -> start ->点击返回键

中间加了start步骤,即使activity销毁之后,service也不会被销毁,只会解绑

案例:

耗时操作放在onStartCommond中执行
实时获取线程中的值,需要bind
bind之后,start执行,然后重复unbind bind操作,就可以通过serviceConn中的方法获取值