C#MD5加密

 protected  string GetMd5String(string str)
        {
            MD5 md5 = MD5.Create();
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(str);
            byte[] strBuffer = md5.ComputeHash(buffer);
            StringBuilder sb = new StringBuilder();
            foreach (byte item in strBuffer)
            {
                sb.Append(item.ToString("x2"));
            }
            return sb.ToString();
        }