ASP.NET 根路径的获取

private string _ApplicationPath;
        /// <summary>
        /// 虚拟应用程序根路径
        /// </summary>
        public string ApplicationPath
        {
            get
            {
                _ApplicationPath = HttpContext.Current.Request.ApplicationPath;
                if (_ApplicationPath.Length == 1)
                {
                    _ApplicationPath = "";
                }
                return _ApplicationPath;
            }
        }
        private string _CurrentPath;
        /// <summary>
        /// 当前的绝对路径
        /// </summary>
        public string CurrentPath
        {
            get
            {
                _CurrentPath = HttpContext.Current.Server.MapPath(".").ToLower();//当前的绝对路径(这里MapPath里的"."代表当前服务器)
                
                if (_CurrentPath.Length == 1)
                {
                    _CurrentPath = "";
                }
                return _CurrentPath;
            }
        }
        private string _RootPath;
        /// <summary>
        /// 系统的根目录
        /// </summary>
        public string RootPath
        {
            get
            {

                _RootPath = HttpContext.Current.Server.MapPath(HttpContext.Current.Request.ApplicationPath).ToLower();//当前的绝对路径           
                if (_RootPath.Length == 1)
                {
                    _RootPath = "";
                }
                return _RootPath;
            }
        }