Android Service的两种使用方法

调用startServise和stopService即可

final Intent intent = new Intent(MainActivity.this,StartService.class);
        start.setonClickListener(new View.onClickListener() {
            @Override
            public void onClick(View view) {
                startService(intent);
            }
        });
        stop.setonClickListener(new View.onClickListener() {
            @Override
            public void onClick(View view) {
                stopService(intent);
            }
        });

onCreate方法只调用一次   onStartCommand方法会调用多次

    @Override
    public void onCreate() {
        super.onCreate();
        Log.e(TAG,"onCreate");
        mediaPlayer  =  MediaPlayer.create(this,R.raw.music);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e(TAG,"onStartCommand");
        if(mediaPlayer.isPlaying()){
            mediaPlayer.pause();
        }
        else {
            mediaPlayer.start();
        }
        return super.onStartCommand(intent, flags, startId);

    }
    
    @Override
    public void onDestroy() {
        Log.e(TAG,"onDestroy");
        mediaPlayer.release();
        super.onDestroy();
    }

定义ServiceConnection  

onServiceConnected在onBind时调用

onServiceDisconnected在正常情况下是不被调用的，它的调用时机是当Service服务被异外销毁时，例如内存的资源不足时这个方法才被自动调用。

 ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            Log.e(getClass().getName(),"onServiceConnected");
            myBinder = (BindService.MyBinder) iBinder;
            myBinder.startMusic();
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            Log.e(getClass().getName(),"onServiceDisconnected");
        }
    };

 final Intent intent1 = new Intent(MainActivity.this,BindService.class);
        bind.setonClickListener(new View.onClickListener() {
            @Override
            public void onClick(View view) {
                bindService(intent1,serviceConnection,BIND_AUTO_CREATE);
            }
        });
        unbind.setonClickListener(new View.onClickListener() {
            @Override
            public void onClick(View view) {
                unbindService(serviceConnection);
            }
        });

service的生命周期如下  onCreate----》onBind-----》onUnbind-----》onDestroy

    MyBinder myBinder = new MyBinder();
    MediaPlayer mediaPlayer;
    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
       // throw new UnsupportedOperationException("Not yet implemented");
        Log.e(TAG,"onBind");
        return myBinder;
    }

    @Override
    public void onCreate() {
        Log.e(TAG,"onCreate");
        mediaPlayer  =  MediaPlayer.create(this,R.raw.music);
        super.onCreate();
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.e(TAG,"onUnbind");
        return super.onUnbind(intent);
    }

    @Override
    public void onDestroy() {
        Log.e(TAG,"onDestroy");
        mediaPlayer.release();
        super.onDestroy();
    }


    class MyBinder extends Binder{
        public void startMusic(){
            if(!mediaPlayer.isPlaying()){
                mediaPlayer.start();
            }
        }

        public void stopMusic(){
            if(mediaPlayer.isPlaying()){
                mediaPlayer.stop();
            }
        }
    }