C# Redux replica

redux in c sharp.cs

using System;
//using System.Web.Extensions;
//using System.Web.Script.Serialization;

/************************************************
 * State
 ***********************************************/

public abstract class State<SubClassState>
{
    public SubClassState ShallowCopy()
    {
        return (SubClassState)this.MemberwiseClone();
    }
}

public class UserState : State<UserState>
{
    public bool signedIn = false;
    public string name = "";
    public int signIns = 0;
}

public class AppState : State<AppState>
{
    public UserState userState = new UserState();

    public override string ToString()
    {
        //return "AppState: " + new JavaScriptSerializer().Serialize(obj);
        return "AppState: - " + userState.name + " - " + userState.signedIn + " - " + userState.signIns;
    }
}

/************************************************
 * Actions
 ***********************************************/

public class Action
{
}

public class ActionUserSignedIn : Action
{
    public string UserName;
}

/************************************************
 * Reducers
 ***********************************************/

public class UserReducer
{
    public static UserState Reduce(UserState userState, Action action)
    {

        //if (action is ActionUserSignedIn ac)
        if (action is ActionUserSignedIn)
        {
            userState = userState.ShallowCopy();
            userState.name = ((ActionUserSignedIn)action).UserName;
            userState.signedIn = true;
            userState.signIns += 1;
        }

        return userState;
    }
}

public class AppReducer
{
    public static AppState Reduce(AppState appState, Action action)
    {
        bool changed = false;
        UserState userState = UserReducer.Reduce(appState.userState, action);
        changed = changed || userState != appState.userState;
        
        if (changed)
        {
            appState = appState.ShallowCopy();
    	    appState.userState = userState;
        }
    	
        return appState;
    }
}

/************************************************
 * Store
 ***********************************************/

public class Store
{
    AppState appState;

    public Store()
    {
        appState = new AppState();
    }

    public void Dispatch(Action action)
    {
        appState = AppReducer.Reduce(appState, action);
    }
	
    public AppState GetState()
    {
        return appState;
    }
}

public class Program
{
    public static void Main()
    {
        Store store = new Store();
        Console.WriteLine(store.GetState());
        store.Dispatch(new ActionUserSignedIn(){ UserName = "Alex" });
        Console.WriteLine(store.GetState());
    }
}