自定义跟随手指移动view

public class MoveView extends AppCompatButton {
    int mLastX;
    int mLastY;
    public MoveView(Context context) {
        super(context);
    }
    public MoveView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        //获取手指当前的坐标
        int x = (int) event.getRawX();
        int y = (int) event.getRawY();

        switch (event.getAction()){
            case MotionEvent.ACTION_MOVE:
                //现在手指的坐标 - 上次view的坐标
                int deltaX= x - mLastX;
                int deltaY = y- mLastY;

                Log.d("shj--","move ,deltax:"+deltaX+" deltay:"+deltaY);

                //用nineoldandroids实现
                int translationx = (int) (ViewHelper.getTranslationX(this)+deltaX);
                int translationy = (int) (ViewHelper.getTranslationY(this)+deltaY);
                ViewHelper.setTranslationX(this,translationx);
                ViewHelper.setTranslationY(this,translationy);

                break;
        }
        mLastY = y;
        mLastX = x;
        return true;
    }
}