using System;

public class Program

{

    public static void Main()

    {

        string str;

        string syskey = "123456789";

        str = GenSignature(syskey,"foo","20170426001757");

        Console.WriteLine(str);

    }

    public static string GenSignature(string syskey,params string[] paramValues)

    {

        string source = "";

        for (int i = 0; i < paramValues.Length; i++)

        {

            if (!string.IsNullOrEmpty(paramValues[i]))

            {

                source += "&" + paramValues[i];

            }

        }

​

        if (string.IsNullOrEmpty(source))

        {

            return "";

        }

​

        source +=  "&" + syskey;

        using (System.Security.Cryptography.MD5 m = System.Security.Cryptography.MD5.Create())

        {

            byte[] hashData = m.ComputeHash(System.Text.UTF8Encoding.UTF8.GetBytes(source));

            return BitConverter.ToString(hashData).Replace("-", "").ToUpper();

        }

    }

}