Android手势左右滑动效果

public class MyRelativeLayout extends RelativeLayout implements GestureDetector.OnGestureListener{  private float mPosX, mPosY, mCurPosX, mCurPosY;  private static final int FLING_MIN_DISTANCE = 20;// 移动最小距离  private static final int FLING_MIN_VELOCITY = 200;// 移动最大速度  //构建手势探测器   GestureDetector mygesture = new GestureDetector(this);  public MyRelativeLayout(Context context){    super(context)  }  public MyRelativeLayout(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    // TODO Auto-generated constructor stub  }  public MyRelativeLayout(Context context, AttributeSet attrs) {    super(context, attrs);    // TODO Auto-generated constructor stub  }    @Override  public boolean onTouchEvent(MotionEvent arg0) {    // TODO Auto-generated method stub    return mDetector.onTouchEvent(arg0);  }  @Override  public boolean onSingleTapUp(MotionEvent e) {    // TODO Auto-generated method stub    return false;  }  @Override  public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,              float distanceY) {    // TODO Auto-generated method stub    return false;  }  @Override  public boolean onDown(MotionEvent e) {    // TODO Auto-generated method stub    return false;  }  @Override  public void onShowPress(MotionEvent e) {    // TODO Auto-generated method stub  }   @Override  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,      float velocityY) {    // TODO Auto-generated method stub    // e1：第1个ACTION_DOWN MotionEvent      // e2：最后一个ACTION_MOVE MotionEvent      // velocityX：X轴上的移动速度（像素/秒）      // velocityY：Y轴上的移动速度（像素/秒）      // X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒      //向左     if (e1.getY() - e2.getY() > FLING_MIN_DISTANCE){   //           && Math.abs(velocityX) > FLING_MIN_VELOCITY) {         collapse();       }      //向上     if (e2.getY() - e1.getY() > FLING_MIN_DISTANCE              && Math.abs(velocityX) > FLING_MIN_VELOCITY) {    }         return false;     } }