更多.net方法用于动态状态机

Question

我写了一个简单的动态FSM.Dynamic表示状态转换是动态的而不是静态的,如图所示ConcreteStateB.

namespace FSM_Example
{
    using System;

    class Program
    {
        static void Main()
        {
            var context = new Context(new ConcreteStateA());
            context.Run();
            Console.Read();
        }
    }

    abstract class State
    {
        public abstract void Execute(Context context);
    }

    class ConcreteStateA : State
    {
        public override void Execute(Context context)
        {
            context.State = new ConcreteStateB();
        }
    }

    class ConcreteStateB : State
    {
        public override void Execute(Context context)
        {
            Console.Write("Input state: ");
            string input = Console.ReadLine();
            context.State = input == "e" ? null : new ConcreteStateA();
        }
    }

    class Context
    {
        private State _state;

        public Context(State state)
        {
            State = state;
        }

        public State State
        {
            get { return _state; }
            set
            {
                _state = value;
                Console.WriteLine("State: " + _state.GetType().Name);
            }
        }

        public void Run()
        {
            while (_state != null)
            {
                _state.Execute(this);
            }
        }
    }
}

这实现了如上所述的状态机GoF305.

因为我是C#和.net的新手:是否有更好的方法可以使用.net或更具体的功能来实现这一目标C#？

Answer 1

Outcoldman的答案提供了许多很棒的选择.

现在,我知道根据模式,下面的代码不是一个合适的FSM,但对于非常简单的实现,它可以帮助您避免编写大量额外的子类.这只是决定工作的正确工具的问题.这个主要关注Action<T>泛型委托的使用:

public class Context
{
    public Action<Context> State { get; internal set; }

    public Context(Action<Context> state)
    {
        State = state;
    }

    public void Run()
    {
        while (State != null)
        {
            State(this);
        }
    }
}

并将"状态机"视为:

public static class SimpleStateMachine
{
    public static void StateA(Context context)
    {
        context.State = StateB;
    }
    public static void StateB(Context context)
    {
        Console.Write("Input state: ");
        var input = Console.ReadLine();
        context.State = input == "e" ? (Action<Context>)null : StateA;
    }
}

为了开始您使用的过程:

var context = new Context(SimpleStateMachine.StateA);
context.Run();
Console.Read();

此外,对于不相关的状态,您也可以使用Lambda表达式,例如:

Action<Context> process = context =>
    {
        //do something
        context.State = nextContext =>
            {
                //something else
                nextContext.State = null;
            };
    };