C#的MD5加密解密的通用操作类 .

  public static class MD5Common
  {
      /// <summary>
      /// 返回指定字符串的Md5
      /// </summary>
      /// <param name="strInput">指定字符串</param>
      /// <returns>返回字符串的Md5</returns>
      public static string GetMd5Hash(string strInput)
      {
          // Create a new instance of the MD5CryptoServiceProvider object.
          MD5 md5Hasher = MD5.Create();

          // Convert the input string to a byte array and compute the hash.
          byte[] btData = md5Hasher.ComputeHash(Encoding.Default.GetBytes(strInput));

          // Create a new Stringbuilder to collect the bytes
          // and create a string.
          StringBuilder sBuilder = new StringBuilder();

          // Loop through each byte of the hashed data
          // and format each one as a hexadecimal string.
          for (int i = 0; i < btData.Length; i++)
          {
              sBuilder.Append(btData[i].ToString("x2"));
          }

          // Return the hexadecimal string.
          return sBuilder.ToString();
      }

      /// <summary>
      /// 检查一个普通字符串的Md5，与传递的Md5字符串是否相同
      /// </summary>
      /// <param name="strInput">普通字符串</param>
      /// <param name="strHash">Md5字符串</param>
      /// <returns>返回是否相同</returns>
      public static bool VerifyMd5Hash(string strInput, string strHash)
      {
          // Hash the input.
          string strhashOfInput = GetMd5Hash(strInput);

          // Create a StringComparer an comare the hashes.
          StringComparer comparer = StringComparer.OrdinalIgnoreCase;

          if (0 == comparer.Compare(strhashOfInput, strHash))
          {
              return true;
          }
          else
          {
              return false;
          }
      }

  }