将文件拷贝到指定目录：

        public void CopyDirIntoDestDirectory(string sourceFileName, string destFileName, bool overwrite)
        {
            if (!Directory.Exists(destFileName))
            {
                Directory.CreateDirectory(destFileName);
            }

            foreach (var file in Directory.GetFiles(sourceFileName))
            {
                File.Copy(file, Path.Combine(destFileName, Path.GetFileName(file)), overwrite);
            }

            foreach (var d in Directory.GetDirectories(sourceFileName))
            {
                CopyDirIntoDestDirectory(d, Path.Combine(destFileName, Path.GetFileName(d)), overwrite);
            }
        }