问在图库中实现垂直滑动时出现问题

EN

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
{
    if (m_curTouchPos == NO_CURRENT_TOUCH_POS || m_callback == null)
        return super.onFling(e1, e2, velocityX, velocityY);

    float e1x = e1.getX();
    float e1y = e1.getY();
    float e2x = e2.getX();
    float e2y = e2.getY();

    float offPath = Math.abs(e1x - e2x);
    float distance = Math.abs(e1y - e2y);

    if (offPath < s_swipeMaxOffPath && 
        //Math.abs(velocityY) >= s_swipeMinVelocity && 
        distance >= s_swipeMinDistance)
    {
        if (e1y > e2y)
        {
            m_callback.onSwipeUp(m_curTouchPos);
            //return true;
        }
        else if (e2y > e1y)
        {
            //TODO: IMPLEMENT THIS
            //m_callback.onSwipeDown(m_curTouchPos);
            //return true;
        }
    }

    m_curTouchPos = NO_CURRENT_TOUCH_POS;
    return super.onFling(e1, e2, velocityX, velocityY);
}

@Override
public boolean onDown(MotionEvent eve)
{
    m_curTouchPos = pointToPosition((int)eve.getX(), (int)eve.getY());
    return super.onDown(eve);
}