using System.ServiceModel;

namespace CHAT
{
    public class ServerUser
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public OperationContext operationContext { get; set; }
    }
}


using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;

namespace CHAT
{
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
    public class Service1 : IService1
    {
        List<ServerUser> users = new List<ServerUser>();
        int nextId = 1;
        public int Connect(string name)
        {
            ServerUser user = new ServerUser();
            {
                ID = nextId;
                Name = name;
                operationContext = OperationContext.Current;
            };
            ++nextId;
            users.Add(user);
            return user.ID;
        }
    }
}