Unity中为UGUI中的Image置空

public class ImageChange : MonoBehaviour {
    //获取的是原来的空图片
    private Sprite FormatSprite;
    public Sprite ChangeSprite;
    private void Start()
    {
        FormatSprite = transform.GetComponent<Image>().sprite;
    }
    void Update () {
        if (Input.GetKeyDown(KeyCode.Alpha1))
        {
            transform.GetComponent<Image>().sprite = FormatSprite;
        }
        if (Input.GetKeyDown(KeyCode.Alpha2))
        {
            transform.GetComponent<Image>().sprite = ChangeSprite;
        }
    }
}