public static string EncryptWithMD5(string source)
        {
            byte[] sor = Encoding.UTF8.GetBytes(source);
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(sor);
            StringBuilder strbul = new StringBuilder(40);
            for (int i = 0; i < result.Length; i++)
            {
                strbul.Append(result[i].ToString("x2"));//加密结果"x2"结果为32位,"x3"结果为48位,"x4"结果为64位

            }
            return strbul.ToString();
        }