System.Tuple cannot be serialized because it does not have a parameterless constructor

Question

Im trying to create a simple Web Service containing only one function which return a Tuple items, the issue is after deploying the ASMX file this error appear:

the function that cause this issue is :

 [WebMethod]
        public Tuple<String[],String> BeginTest(String url, String ip_public, int port_external, String ip_internal, int port_inner, bool isInner)
        {
            Ping ping = new Ping();
            String errorMSG = "Null";
            String[] info = new string[3];
            PingReply pingreply = null;

            try
            {
                if (isInner)
                {
                     pingreply = ping.Send(ip_internal);
                }
                else
                {
                     pingreply = ping.Send(ip_public);
                }

                info[0] = pingreply.RoundtripTime.ToString() ;
                info[1] = pingreply.Options.Ttl.ToString();
                info[2] = pingreply.Buffer.Length.ToString();


            }
            catch (Exception err)
            {
                errorMSG = err.Message.ToString();
            }

            return new Tuple<string[], string>(info, errorMSG);



        }

Answer 1

Create your own tuple class, called MyTuple, that does have a parameterless constructor.

public class MyTuple<TypeParameter1, TypeParameter2>
{
    public TypeParameter1 Value1 { get; set; }
    public TypeParameter2 Value2 { get; set; }

    public MyTuple()
    {

    }
    public MyTuple(TypeParameter1 value1, TypeParameter2 value2)
    {
        Value2 = value2;
        Value1 = value1;
    }
}

More info here: https://www.codeproject.com/Articles/1052516/Csharp-Generics-for-beginners-Part