1.改變RectTransform的top

GetComponent<RectTransform>().offsetMax = new Vector2(GetComponent<RectTransform>().offsetMax.x, top);

2.改變RectTransform的bottom

GetComponent<RectTransform>().offsetMin = new Vector2(GetComponent<RectTransform>().offsetMin.x, bottom);

3.改變RectTransform的width，height

GetComponent<RectTransform>().sizeDelta = new Vector2(width, height);

4.改變RectTransform的pos

GetComponent<RectTransform>().anchoredPosition3D = new Vector3(posx,posy,posz);

GetComponent<RectTransform>().anchoredPosition = new Vector2(posx,posy);