UGUI BoxCollider自适应大小

 NGUI下给Sprite/image添加collider后能自适应大小，但是在UGUI下Collider是默认在（0，0）位置，size为0

因此写了个简单的脚本：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BoxColliderAdjust : MonoBehaviour
{

    private BoxCollider2D boxCollider2D;
    private RectTransform rt;//UI图片

    void Start()
    {
        rt = this.GetComponent<RectTransform>();
        boxCollider2D = this.GetComponent<BoxCollider2D>();

        boxCollider2D.offset = rt.rect.center;//把box collider设置到物体的中心
        boxCollider2D.size = new Vector2(rt.rect.width, rt.rect.height);//改变collider大小
    }

    void Update()
    {
        
    }
           
}