public interface OnProgressListener {

    void onProgress(int progress);

}

public class MyService extends Service {

    private int progress = ;

    private OnProgressListener onProgressListener;

    class DownLoadBinder extends Binder{

        public MyService getService(){

            return MyService.this;

        }

    }

    // 设置回调接口

    public void setOnProgressListener(OnProgressListener onProgressListener){

        this.onProgressListener = onProgressListener;

    }

    @Nullable

    @Override

    public IBinder onBind(Intent intent) {

        return new DownLoadBinder();

    }

    @Override

    public void onCreate() {

        super.onCreate();

    }

    @Override

    public int onStartCommand(Intent intent, int flags, int startId) {

        return super.onStartCommand(intent, flags, startId);

    }

    // 模拟下载

    public  void startDownload(){

        new Thread(new Runnable() {

            @Override

            public void run() {

                while (progress<){

                    progress += ;

                    // 通知调用方

                    if( onProgressListener != null  ){

                        onProgressListener.onProgress(progress);

                    }

                    try {

                        Thread.sleep();

                    }catch (InterruptedException e){

                        e.printStackTrace();

                    }

                }

            }

        }).start();

    }

    // 获取progress

    public int getProgress(){

        return progress;

    }

    @Override

    public void onDestroy() {

        super.onDestroy();

        Log.e("Service", "onDestroy");

    }

}

public class MainActivity extends Activity {

    private ProgressBar progressBar;

    private MyService myService;

    private int progress = ;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        progressBar = (ProgressBar)findViewById(R.id.progressBar);

        Intent intent = new Intent(this, MyService.class);

        // 标志位BIND_AUTO_CREATE是的服务中onCreate得到执行,onStartCommand不会执行

        bindService(intent,conn, Context.BIND_AUTO_CREATE);

    }

    protected void myClick(View v){

        if( v.getId() == R.id.btn ){

            myService.startDownload();

        }

        if( v.getId() == R.id.btn2 ){

            unbindService(conn);

        }

    }

    @Override

    protected void onPause() {

        super.onPause();

    }

    @Override

    protected void onStop() {

        super.onStop();

    }

    @Override

    protected void onDestroy() {

    unbindService(conn);

        super.onDestroy();

    }

    ServiceConnection conn = new ServiceConnection() {

        @Override

        public void onServiceConnected(ComponentName name, IBinder service) {

            myService = ((MyService.DownLoadBinder)service).getService();

            // 回调接口

            myService.setOnProgressListener(new OnProgressListener() {

                @Override

                public void onProgress(int progress) {

                    progressBar.setProgress(progress);

                }

            });

        }

        @Override

        public void onServiceDisconnected(ComponentName name) {

        }

    };

}