当调用TweenPosition.Begin()时，gameObject会被自动挂上TweenPosition脚本

 //让gameObject在20内移到坐标(4, 0, 0)

TweenPosition tween = TweenPosition.Begin(gameObject, 20, new Vector3(4, 0, 0));
tween.PlayForward();

 //若想在中途停止移动

TweenPosition tween = gameObject.GetComponent<TweenPosition>();

tween.enabled = false;