Question

我正在开始Android开发，现在正在学习服务我已经创建了一个简单的服务来连续烘烤一个字符串我拿了两个按钮开始和停止服务当我点击开始按钮时，服务启动并且它连续地烘烤字符串但是当我通过点击停止按钮停止服务时，它不会停止它将继续烘烤字符串。

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();

        doToast();

        return START_STICKY;
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
    }


    public void doToast()
    {
        final Handler handler= new Handler();
        handler.postDelayed(new Runnable(){

            @Override
            public void run() {
                // TODO Auto-generated method stub
                Toast.makeText(MyService.this, "hi", 0).show();
                handler.postDelayed(this, 3000);
            }

        }, 3000);

    }

}

这是启动和停止服务的代码

startservice.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        startService(new Intent(getBaseContext(), MyService.class));
    }
});

stopservice.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        stopService(new Intent(getBaseContext(), MyService.class));
    }
});

Answer 1

正如MD所提到的，即使你正在停止服务，你也必须删除回调，因为runnable仍然在消息队列中，等待再次发布。那就是：

public class AwesomeService extends Service {
// other stuff
  private int DELAY = 2000;
  Handler mHandler = new Handler();
  Runnable toastRunnable;
  public void doToast() {
    mHandler.postDelayed(getToastRunnable(), DELAY);
  }
  private Runnable getToastRunnable() {
    Runnable r = new Runnable() { 
      @Override public void run() {
        // show toast
        // doToast()
      }
    };
    toastRunnable = r;
    return r;
  }
...
  // and to remove the callbacks,
  @Override public void onDestroy() {
    super.onDestroy();
    mHandler.removeCallbacks(toastRunnable);
  }
}

如何停止后台服务？

1 个答案: