Android服务

Question

你好我是android的新手。我创建了一个服务来检测屏幕上的手势。为了获得触摸事件，我动态地创建了一个视图视图并将其添加到窗口管理器。我能够触摸，但我无法获得手势。它显示＆＃34; dispatchTouchEvent＆＃34;方法错误。我用活动试了一下它运行正常。这是我的代码

public class GestureActivity extends Activity implements OnGestureListener
{ 
    TextView textview;
    GestureDetector detector;
    @Override
    public void onCreate(Bundle savedInstanceState) 
    { 
        super.onCreate(savedInstanceState);
        textview = new TextView(this);
        textview.setText("Gesture Demo");
        detector=new GestureDetector(this); 
        setContentView(textview);

    }
    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {

     return detector.onTouchEvent(event); 

    }

    @Override 
    public boolean onDown(MotionEvent e)

    {

      Toast.makeText(getApplicationContext(), "OnDown Gesture", 100).show(); return false; 

    }

    @Override 
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
    { 
        Toast.makeText(getApplicationContext(), "Fling Gesture", 100).show(); return true;

    }
    @Override 
    public void onLongPress(MotionEvent e) 
    {

        Toast.makeText(getApplicationContext(), "Long Press Gesture", 100).show(); 

    }
    @Override 
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) 
    {
        Toast.makeText(getApplicationContext(), "Scroll Gesture", 100).show(); return false;

    }
    @Override
    public void onShowPress(MotionEvent e)
    { 
        Toast.makeText(getApplicationContext(), "Show Press gesture", 100).show();

    }
    @Override 
    public boolean onSingleTapUp(MotionEvent e)
    {

        Toast.makeText(getApplicationContext(), "Single Tap Gesture", 100).show();
        return true;
    }
}

如何通过动态添加视图在服务中获取此手势？