C# 字段加密解密代码

/// <summary> /// DES加密字符串[加密密钥为computer] /// </summary> /// <param name="encryptString">待加密的字符串</param> /// <param name="encryptKey">加密密钥,要求为8位</param> /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>