C# 文件复制帮助类

/// <summary>
    /// 文件帮助类
    /// </summary>
    public class filehelper
    {
        /// <summary>
        /// 复制一个目录下所有文件到一个新目录下
        /// </summary>
        /// <param name="copypath">原目录</param>
        /// <param name="newfilepathfunc">新目录生成方法</param>
        /// <param name="iscopysubfolder">是否复制子文件夹内的文件</param>
        /// <param name="isoverwrite">可选：是否覆盖(默认覆盖)</param>
        public static void copyfilelist(string copypath, func<string, string> newfilepathfunc, bool iscopysubfolder = true, bool isoverwrite = true)
        {
            //复制当前目录下所有文件到新目录中
            list<string> filelist = directory.getfiles(copypath).tolist();

            foreach (var filepath in filelist)
            {
                string newfilepath = newfilepathfunc(filepath);
                string newfiledirectory = newfilepath.substring(0, newfilepath.lastindexof('\\') + 1);
                if (!directory.exists(newfiledirectory))
                {
                    directory.createdirectory(newfiledirectory);
                }

                if (isoverwrite || !file.exists(newfilepath))
                {
                    file.copy(filepath, newfilepath, isoverwrite);
                }

            }

            //复制子目录下所有文件到新目录中
            if (iscopysubfolder)
            {
                list<string> subfolderlist = directory.getdirectories(copypath).tolist();
                foreach (var subfolder in subfolderlist)
                {
                    filehelper.copyfilelist(subfolder, newfilepathfunc, iscopysubfolder, isoverwrite);
                }
            }

        }

        /// <summary>
        /// 复制一组文件到一个新目录下
        /// </summary>
        /// <param name="filepathlist">文件列表</param>
        /// <param name="newfilepathfunc">新目录生成方法</param>
        /// <param name="isoverwrite">可选：是否覆盖(默认覆盖)</param>
        public static void copyfilelist(list<string> filepathlist, func<string, string> newfilepathfunc, bool isoverwrite = true)
        {
            //将上月保存未改变多币种数据复制到本月中（本月已存在多币种数据不覆盖）
            foreach (var filepath in filepathlist)
            {
                string newfilepath = newfilepathfunc(filepath);
                string newfiledirectory = newfilepath.substring(0, newfilepath.lastindexof('\\') + 1);
                if (!directory.exists(newfiledirectory))
                {
                    directory.createdirectory(newfiledirectory);
                }

                if (isoverwrite || !file.exists(newfilepath))
                {
                    file.copy(filepath, newfilepath, isoverwrite);
                }
            }
        }

    }