/// <summary>
 /// DES 解密(数据加密标准,速度较快,适用于加密大量数据的场合)
 /// </summary>
 /// <param name="decryptString">待解密的密文</param>
 /// <param name="decryptKey">解密的密钥,必须为8位</param>
 /// <returns>解密后的明文</returns>
 public static string DESDecrypt(this string decryptString, string decryptKey)
 {
     return(CryptoUtility.DESDecrypt(decryptString, decryptKey));
 }