在活动中停止Android服务

Question

I'm having trouble STOPPING the StimulationService , I'm not sure if i'm calling the stopservice method correctly from my activity. Any help will be much appreciated.

Activity to start and stop Service

     public class Stimulation extends Activity implements OnClickListener {
  private static final String TAG = "StimulationActivity";
  Button buttonStart, buttonStop;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(com.someapp.Activities.R.layout.stimulation);

    buttonStart = (Button) findViewById(com.someapp.Activities.R.id.ButtonStart);
    buttonStop = (Button) findViewById(com.someapp.Activities.R.id.ButtonStop);

    buttonStart.setOnClickListener(this);
    buttonStop.setOnClickListener(this);
  }

  public void onClick(View src) {
    switch (src.getId()) {
    case com.someapp.Activities.R.id.ButtonStart:
      Log.d(TAG, "onClick: starting service");
      startService(new Intent(this, StimulationService.class));
      break;
    case com.someapp.Activities.R.id.ButtonStop:
      Log.d(TAG, "onClick: stopping service");
      stopService(new Intent(this, StimulationService.class));
      break;
    }
  }
}

}

Service

     public class StimulationService extends Service {
private static final String TAG = "StimulationService";
private IOIO ioio_;
private DigitalOutput led       


private volatile IOIOThread ioio_thread_;

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


public void onCreate() {
    Toast.makeText(this, "My Service Created", Toast.LENGTH_LONG).show();       
    Log.d(TAG, "onCreate");

}

public void onDestroy() {
    Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show();
    Log.d(TAG, "onDestroy");
    ioio_thread_.stop();

}

public void onStart(Intent intent, int startid) {
    Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show();
    Log.d(TAG, "onStart");
    ioio_thread_ = new IOIOThread();
    ioio_thread_.start();

}

public void onStop(Intent intent, int stopid) {
    Log.d(TAG, "stop()");
    ioio_thread_ = null;
}


class IOIOThread extends Thread {
    private IOIO ioio_;
    private DigitalOutput led;

    /** Thread body. */
    public void run() {
        Thread thisThread = Thread.currentThread();
        super.run();

        while (ioio_thread_ == thisThread) {
            ioio_ = IOIOFactory.create();
            try{
                Log.d(TAG, "Wait for IOIO Connection");
                ioio_.waitForConnect();
                Log.d(TAG, "IOIOConnected");

                while (true) {
                    intializePins();
                    Log.d(TAG, "Pins Intialized");
                    while(true){
                        led.write(false);
                        sleep(2000);
                        led.write(true);
                        sleep(2000);
                    }
                }

            }


            catch (ConnectionLostException e) {
            } catch (Exception e) {
                Log.e("Hello", "Unexpected exception caught", e);
                ioio_.disconnect();
                break;
            } finally {
                try {
                    ioio_.waitForDisconnect();
                } catch (InterruptedException e) {
                }
            }
        }
    }

}

Answer 1

First, as @Waqas notes, there is no onStop() method. There is an onDestroy() method, which will be called after stopService() is called.

Second, you are not stopping the background thread ever. Simply setting the ioio_thread_ data member to null does not stop the thread. That thread will keep running forever. Please do not do this. If nothing else, use an AtomicBoolean instead of a hardwired true in your while() loop, and flip that AtomicBoolean to false in onDestroy() .

Answer 2

Your activity is OK. The problem is that the service is not killing the IOIOThread. Thread.stop() is deprecated and will not do what you want anyway. What you want is to call ioio_.disconnect() from the service's onStop() (through a method on your thread class), and then join() the thread. See AbstracIOIOActivity as an example. With minor modifications it can be turned into AbstractIOIOService , and will enable you to leave you application-specific logic in a subclass.