Unity fsm有限状态机的实现

FSM

using UnityEngine;

public class FSM<T>
{
    private T owner;
    public IFSMState<T> CurrentState { get; private set; }
    public IFSMState<T> PreviousState { get; private set; }

    public FSM(T owner)
    {
        this.owner = owner;
    }

    public void Update()
    {
        if (CurrentState != null)
        {
            CurrentState.Execute(owner);
        }
    }

    public void ChangeState(IFSMState<T> newState)
    {
        PreviousState = CurrentState;

        if (CurrentState != null)
        {
            CurrentState.Exit(owner);
        }

        CurrentState = newState;

        if (CurrentState != null)
        {
            CurrentState.Enter(owner);
        }
    }

    public void RevertState()
    {
        ChangeState(PreviousState);
    }

    public bool IsCurrentState(IFSMState<T> state)
    {
        if (CurrentState != null)
        {
            return CurrentState.GetType() == state.GetType();
        }

        return false;
    }

    public void Clear()
    {

    }
}

IFSMState

using UnityEngine;
using System.Collections;

public interface IFSMState<T>
{
    void Enter(T owner);

    void Execute(T owner);

    void Exit(T owner);
}

RoleCtrl 

using Pathfinding;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using UnityEngine.UI;

public class RoleCtrl : MonoBehaviour
{
    //状态
    [HideInInspector] [NonSerialized] public FSM<RoleCtrl> fsm;      

    private void Awake()
    {
        this.fsm = new FSM<RoleCtrl>(this);
        this.fsm.ChangeState(new HeroWalkState());
    }

    private void Update()
    {
        if (this.fsm != null)
        {
            this.fsm.Update();
        }
    }   
}

HeroWalkState 

using UnityEngine;
using System.Collections;
using System.IO;

//走路状态
public class HeroWalkState : IFSMState<RoleCtrl>
{    
    public void Enter(RoleCtrl owner)
    {
        //初始化
    }

    public void Execute(RoleCtrl owner)
    {
        //update更新
    }

    public void Exit(RoleCtrl owner)
    {
        //销毁
    }
}