C# Md5Hash的用法及实例

/// <summary>          /// MD5　32位加密(大写)          /// </summary>          /// <param name="str"></param>          /// <returns></returns>          static string UserMd5(string str)          {              string cl = str;              string pwd = "";              MD5 md5 = MD5.Create();//实例化一个md5对像              // 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择　              byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));              // 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得              for (int i = 0; i < s.Length; i++)              {                  // 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符                     pwd = pwd + s[i].ToString("X");                }              return pwd;          }          /// <summary>          /// MD5 16位加密 加密后密码为小写          /// </summary>          /// <param name="ConvertString"></param>          /// <returns></returns>          public static string GetMd5str(string ConvertString)          {              MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();              string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);              t2 = t2.Replace("-", "");              t2 = t2.ToLower();              return t2;          }          /// <summary>          /// MD5 16位加密 加密后密码为大写          /// </summary>          /// <param name="ConvertString"></param>          /// <returns></returns>          public static string GetMd5Str(string ConvertString)          {              MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();              string t2 = BitConverter.ToString(md5.ComputeHash(UTF8Encoding.Default.GetBytes(ConvertString)), 4, 8);              t2 = t2.Replace("-", "");              return t2;          }          /// <summary>          /// MD5加密(小写)          /// </summary>          /// <param name="input"></param>          /// <returns></returns>          private static string Md5Hash(string input)          {              MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();              byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));              StringBuilder sBuilder = new StringBuilder();              for (int i = 0; i < data.Length; i++)              {                  sBuilder.Append(data[i].ToString("x2"));              }              return sBuilder.ToString();          }