Question

我正在尝试为我的custom listview实现onTouchListner以检测滑动。在此代码中，两个切换案例（ACTION_DOWN，ACTION_UP）都有效，但当ACTION_UP触发我在downx中获得的值时，downy变为0。并且用于检测滑动的代码总是说向右滑动（即使我只是单击!!）

            view.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) 
        {

            float downx = 0,downy = 0, upx = 0, upy = 0, movex = 0, movey = 0;
                switch(event.getAction())
                {


                    case(MotionEvent.ACTION_DOWN):
                    {
                        downx = event.getX();
                        downy = event.getY();
                        Log.i("TOUCH","DOWN");
                        break;

                    }                       

                    case(MotionEvent.ACTION_UP):
                    {
                        upx = event.getX();
                        upy = event.getY();
                        Log.i("TOUCH","UP");
                        if(downx  < upx)
                        {
                            Log.w("TODO","Swiped right");

                        }
                        else if(upx < downx)
                        {
                            Log.w("TODO","Swiped left");
                        }

                        break;
                    }

            }

                Log.i("TOUCH_DOWN","x = "+downx+"y = "+ downy); 
                Log.i("TOUCH_MOVE","x = "+movex+"y = "+ movey); 
                Log.i("TOUCH_UP","x = "+upx+"y = "+ upy);   

            return true;
        }
    });



    return view;
}

}

有没有办法让它发挥作用建议需要!! 感谢

Answer 1

  @Override
  public boolean onTouch(View v, MotionEvent event)  {
       float downx = 0,downy = 0, upx = 0, upy = 0, movex = 0, movey = 0;

每次触摸事件都会调用

onTouch，重新初始化所有本地成员。如果你想避免这种情况，请将其保留为班级成员，

Answer 2

   float downx = 0,downy = 0, upx = 0, upy = 0, movex = 0, movey = 0;

每次调用onTouch（）时都会初始化它们将它们全局声明为类成员。

MotionEvent.ACTION_UP无法正常工作

2 个答案: