/// <summary>
 /// 加密字符串
 /// </summary>
 /// <param name="originalStr">原字符串</param>
 /// <returns></returns>
 public static string EncryptString(string originalStr)
 {
     SymmetrySecret s = new SymmetrySecret(originalStr);
     return s.Encrypt().Replace("=", "aaaaadddd").Replace("?", "cccc99").Replace("/", "dddd99").Replace("&", "rrrr66").Replace(@"\", "ffffii").Replace("+", "ssss876");
 }
 /// <summary>
 /// 解密字符串
 /// </summary>
 /// <param name="encryptStr">要解密的字符串</param>
 /// <returns></returns>
 public static string DecryptString(string encryptStr)
 {
     SymmetrySecret s = new SymmetrySecret(encryptStr.Replace("aaaaadddd", "=").Replace("cccc99", "?").Replace("dddd99", "/").Replace("rrrr66", "&").Replace("ffffii", @"\").Replace("ssss876", "+"));
     return s.Decrypt();
 }