Android 0nTouch 事件问题 [Swipe DOWN and UP]

Question

我有一个需要 onTouch 滑动事件的应用程序，例如 Iphone。他们是

1. 向上滑动。
2. 向下滑动。
3. 向左滑动。
4. 向右滑动。

我实现了 onTouch 事件如下。我得到了正确的向左和向右滑动动作。但这是实现向下和向上滑动动作的正确方法。

我的密码：

    float downXValue,downYValue;

    @Override
    public boolean onTouchEvent(MotionEvent arg1) {

         // Get the action that was done on this touch event
        switch (arg1.getAction())
        {
            case MotionEvent.ACTION_DOWN:
            {
                // store the X value when the user's finger was pressed down
                downXValue = arg1.getX();
                downYValue = arg1.getY();
                break;
            }

            case MotionEvent.ACTION_UP:
            {
                // Get the X value when the user released his/her finger
                float currentX = arg1.getX();   
                float currentY=arg1.getY();

                // going backwards: pushing stuff to the right
                if (downXValue < currentX)
                {
                    Log.d(DEBUG_TAG, "Right");
                }

                // going forwards: pushing stuff to the left
                if (downXValue > currentX)
                {

                    Log.d(DEBUG_TAG, "Left");
                }
                break;
            }
        }

         //GestureListener is called here... 

        //return gestures.onTouchEvent(event);


        return true;
    }

谢谢。

Answer 1

怎么样……

if (downYValue < currentY)
{
    Log.d(DEBUG_TAG, "Down");
}

你确定上面的代码是你写的吗？

编辑

好的，我相信你。你要做的基本上是：

double sizeInX = Math.abs(downXValue - currentX);
double sizeInY = Math.abs(downYValue - currentY);
if( sizeInX > sizeInY ){
   // you better swipe horizontally
} else {
   // you better swipe vertically
}

Answer 2

这是我前段时间写的一个监听器，它可以处理上下滑动。我用来跟踪触摸位置的 float oldPosition 变量。里面有一些不需要的代码，但你会明白的：

    LinearLayout tableM = (LinearLayout) findViewById (R.id.tableM);
    tableM.setOnTouchListener(new OnTouchListener () {
        public boolean onTouch(View view, MotionEvent event) {
            if (event.getAction() == android.view.MotionEvent.ACTION_DOWN) {
                oldPosition = event.getY();
                return true;
            } else
            if (event.getAction() == android.view.MotionEvent.ACTION_MOVE) {
                if (event.getY() < oldPosition) {
                    tableIndexM++;
                    if (tableIndexM > (minsecs.length - 3)) {
                        tableIndexM = 0;
                    }
                    fillTable (rowM0, rowM1, rowM2, minsecs, tableIndexM);
                }
                else if (event.getY() > oldPosition) {
                    tableIndexM--;
                    if (tableIndexM < 0) {
                        tableIndexM = minsecs.length - 3;
                    }
                    fillTable (rowM0, rowM1, rowM2, minsecs, tableIndexM);
                }
                oldPosition = event.getY();
                return true;
            }
            return false;
        }
    });