文件系列--截取路径字符串，获取文件名

/// <summary>
        /// 绝对路径转相对路径
        /// </summary>
        /// <param name="strUrl"></param>
        /// <returns></returns>
        private static string urlConvertor(string strUrl)
        {
            string tmpRootDir = HttpContext.Current.Server.MapPath(System.Web.HttpContext.Current.Request.ApplicationPath.ToString());//获取程序根目录
            string urlPath = strUrl.Replace(tmpRootDir, ""); //转换成相对路径
            urlPath = urlPath.Replace(@"/", @"/");
            return urlPath;
        }
 
        /// <summary>
        /// 相对路径转绝对路径
        /// </summary>
        /// <param name="strUrl"></param>
        /// <returns></returns>
        private static string urlConvertorLocal(string strUrl)
        {
            string tmpRootDir = HttpContext.Current.Server.MapPath(System.Web.HttpContext.Current.Request.ApplicationPath.ToString());//获取程序根目录
            string urlPath = tmpRootDir + strUrl.Replace(@"/", @"/"); //转换成绝对路径
            return urlPath;
}

下面的这种方式简单粗暴；
    class Program
    {
        static void Main(string[] args)
        {
            string str = "fxq.5.6.doc";    //文件名称中设计多个特定符号；
            str = str.Substring(0, str.LastIndexOf("."));
            Console.WriteLine(str);
            Console.Read();
        }

}