android – 拖动时跳转ImageView. getX()和getY()值正在跳跃

这个onTouchListener试图通过跟踪pointerId来解决这个问题.这个onTouchListener的问题是在拖动ImageView时,ImageView非常疯狂地跳转. getX()和getY()值跳转.

我觉得我正确地做到了这一点.我不想为此编写自定义视图,因为我已经实现了scaleGestureDetector并编写了一个有效的自定义rotateGestureDetector.一切正常但我需要解决使用getRawX()和getRawY()时遇到的问题.

有谁知道我在这里做错了什么？

这是我的onTouchListener：

final View.onTouchListener onTouchListener = new View.onTouchListener()
{
    @Override
    public @R_489_8487@an onTouch(View v,MotionEvent event)
    {
        relativeLayoutParams = (RelativeLayout.LayoutParams) v.getLayoutParams();

        final int action = event.getAction();
        switch (action & MotionEvent.ACTION_MASK)
        {
            case MotionEvent.ACTION_DOWN:
            {
                final float x = event.getX();
                final float y = event.getY();

                // Where the user started the drag
                lastX = x;
                lastY = y;
                activePointerId = event.getPointerId(0);
                break;
            }
            case MotionEvent.ACTION_MOVE:
            {
                // Where the user's finger is during the drag
                final int pointerIndex = event.findPointerIndex(activePointerId);
                final float x = event.getX(pointerIndeX);
                final float y = event.getY(pointerIndeX);

                // Calculate change in x and change in y
                final float dx = x - lastX;
                final float dy = y - lastY;

                // update the margins to move the view
                relativeLayoutParams.leftMargin += dx;
                relativeLayoutParams.topMargin += dy;
                v.setLayoutParams(relativeLayoutParams);

                // Save where the user's finger was for the next ACTION_MOVE
                lastX = x;
                lastY = y;

                v.invalidate();
                break;
            }
            case MotionEvent.ACTION_UP:
            {
                activePointerId = INVALID_POINTER_ID;
                break;
            }
            case MotionEvent.ACTION_CANCEL:
            {
                activePointerId = INVALID_POINTER_ID;
                break;
            }
            case MotionEvent.ACTION_POINTER_UP:
            {
                // Extract the index of the pointer that left the touch sensor
                final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
                final int pointerId = event.getPointerId(pointerIndeX);

                if(pointerId == activePointerId)
                {
                    // This was our active pointer going up. Choose a new
                    // active pointer and adjust accordingly
                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                    lastX = (int) event.getX(newPointerIndeX);
                    lastY = (int) event.getY(newPointerIndeX);
                    activePointerId = event.getPointerId(newPointerIndeX);
                }
                break;
            }
        }
        return true;
    }
};
image1.setOnTouchListener(onTouchListener);