/// <summary>
    /// 導航(hang)面包
    /// </summary>
    public class BannerBread
    {
        public string DisplayTitle { get; set; }
        public string Url { get; set; }
        public int ID { get; set; }
        public int ParentID { get; set; }
        public BannerBread Parent { get; set; }
    }

    /// <summary>
    /// 導(dao)航生產(chan)類
    /// </summary>
    public static class BannerBreadFactory
    {
        /// <summary>
        /// BannerBread單例實例對象
        /// </summary>
        static readonly List<BannerBread> Instance = new List<BannerBread>();

        static BannerBreadFactory()
        {
            Instance.Add(new BannerBread { ID = 1, DisplayTitle = "首頁", Parent = null, ParentID = 0, Url = "/" });
            Instance.Add(new BannerBread { ID = 2, DisplayTitle = "關于(yu)我們", Parent = null, ParentID = 1, Url = "/Home/About" });
            Instance.Add(new BannerBread { ID = 3, DisplayTitle = "聯系我們", Parent = null, ParentID = 1, Url = "/Home/Contact" });
        }
        /// <summary>
        /// 得到當前(qian)URL的祖宗(zong)節點
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public static BannerBread GetBanner(string url)
        {
            var entity = Instance.FirstOrDefault(i => i.Url.ToUpper() == url.ToUpper());
            GetFather(entity);
            return entity;
        }
        /// <summary>
        /// 標準的(de)導(dao)航，程序開(kai)發人員(yuan)可以根(gen)據自己的(de)需要，在具體項目中去定義它(ta)
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public static string GenerateStandardBanner(string url)
        {
            var entity = GetBanner(url);
            StringBuilder str = new StringBuilder();
            while (entity != null)
            {
                str.Insert(0, "/<span><a href='" + entity.Url + "'>" + entity.DisplayTitle + "</a></span>");
                entity = entity.Parent;
            }
            return str.ToString().StartsWith("/") ? str.ToString().Substring(1) : "未找到(dao)導航(hang)項";
        }
        /// <summary>
        /// 得到祖宗
        /// </summary>
        /// <param name="son"></param>
        private static void GetFather(BannerBread son)
        {
            if (son != null)
            {
                son.Parent = Instance.FirstOrDefault(i => i.ID == son.ParentID);
                GetFather(son.Parent);
            }
        }

    }