public IEnumerator GetImage(string url, Transform user)  //URL + Transform
    { //加载网络图片
        Image ico = user.GetComponent<Image>();  //获取组件
        ico.color = new Color(1, 1, 1);
        ico.sprite = Resources.Load("Image/yuan" , typeof(Sprite)) as Sprite; //载入进度圆环图片
        ico.preserveAspect = true;  //禁用拉伸
        ico.type = Image.Type.Filled; //修改显示模式
        WWW www = new WWW(url);
        while (!www.isDone)
        { //赋值加载进度
            ico.fillAmount = www.progress;
            yield return null;
        }
        ico.type = Image.Type.Simple;  //还原显示模式
        if (www != null && string.IsNullOrEmpty(www.error))
        {
            Texture2D texture = www.texture;
            Sprite sprite = Sprite.Create(texture, new Rect(0, 0, texture.width, texture.height), new Vector2(0.5f, 0.5f));
            ico.sprite = sprite;
        }
        else
        { //加载失败
            ico.sprite = Resources.Load("Image/ImageError", typeof(Sprite)) as Sprite;
        }
    }