在活动中停止Android服务

Question

我在停止StimulationService时遇到了困难，我不确定是否从我的活动中正确地调用了秒针方法。任何帮助都将不胜感激。

启动和停止服务的活动

     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;
    }
  }
}

}

服务

     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

你的活动没问题。问题是，该服务并没有扼杀IOIOThread。Thread.stop()是不推荐的，无论如何也不会做你想做的事情。您想要的是从服务的ioio_.disconnect() (通过线程类上的一个方法)调用onStop()，然后join()线程。以AbstracIOIOActivity为例。只要稍加修改，就可以将其转换为AbstractIOIOService，并使您能够将特定于应用程序的逻辑留在子类中。

Answer 2

首先，正如@Waqas所指出的，没有onStop()方法。有一个onDestroy()方法，它将在调用stopService()之后调用。

第二，永远不要停止后台线程。简单地将ioio_thread_数据成员设置为null并不会停止线程。那条线将永远运行下去。请不要这样做。如果没有其他的话，在您的AtomicBoolean循环中使用AtomicBoolean而不是硬连接的true，然后将该AtomicBoolean切换到onDestroy()中的false。