private void Update()
    {
        if (isDown)
        {
            //如果触摸移动了
            Vector2 tmp = new Vector2(Input.GetAxis("Mouse X"), Input.GetAxis("Mouse Y"));
            if (tmp.sqrMagnitude >= 0.05)
            {
                Debug.Log("111");
                setChange();
            }

            //更新控制杆位置以及行动
            if (vLenght > r)
            {
                vLenght = r;
                control.setHAndV(-vLenght * moveV.x / r, -vLenght * moveV.y / r);
            }

            else if (vLenght < 0.5 * r)
            {
                control.setHAndV(-vLenght * moveV.x * 0.5f / r, -vLenght * moveV.y * 0.5f / r);
            }
            else
            {
                control.setHAndV(-vLenght * moveV.x / r, -vLenght * moveV.y / r);
            }
            this.smallImage.transform.position = this.smallImageInitPos + new Vector3(-vLenght * moveV.x, -vLenght * moveV.y, 0);
        }
    }