Lua中使用状态机FSM简单例子

FSM 有限状态机：

一个有限状态机是一个设备，或者是一个设备模型，具有有限数量的状态，它可以在任何给定的时间根据输入进行操作，使得一个状态变换到另一个状态，或者是使一个输入或者一种行为的发生。一个有限状态机在任何瞬间只能处在一种状态。

进入动作

退出动作

更新动作

FsmMachine.lua

FsmMachine = {}

function FsmMachine:New()

    self.__index = self

    o = setmetatable({}, self)

    o.states = {}

    o.curState = nil

    return o

end

-- 添加状态

function FsmMachine:AddState(baseState)

    self.states[baseState.stateName] = baseState

end

-- 初始化默认状态

function FsmMachine:AddInitState(baseState)

    self.curState = baseState

end

-- 更新当前状态

function FsmMachine:Update()

    self.curState:OnUpdate()

end

-- 切换状态

function FsmMachine:Switch(stateName)

    if self.curState.stateName ~= stateName then

        self.curState:OnLeave()

        self.curState = self.states[stateName]

        self.curState:OnEnter()

    end

end

状态机基类

BaseState.lua

BaseState = {}

function BaseState:New(stateName)

    self.__index = self

    o = setmetatable({}, self)

    o.stateName = stateName

    return o

end

-- 进入状态

function BaseState:OnEnter()

end

-- 更新状态

function BaseState:OnUpdate()

end

-- 离开状态

function BaseState:OnLeave()

end

测试类

Main.lua

require("BaseState")

require("FsmMachine")

FsmMachineTest = {}

-----[状态A,覆盖BaseState方法]----------------

aState = BaseState:New("aState")

function  aState:OnEnter()

    print("aState:OnEnter()")

end

function  aState:OnUpdate()

    print("aState:OnUpdate()")

end

function  aState:OnLeave()

    print("aState:OnLeave()")

end

-----[状态B,覆盖BaseState方法]----------------

bState = BaseState:New("bState")

function  bState:OnEnter()

    print("bState:OnEnter()")

end

function  bState:OnUpdate()

    print("bState:OnUpdate()")

end

function  bState:OnLeave()

    print("bState:OnLeave()")

end

-----[测试状态机]-----------------------------

fsm = FsmMachine:New()

fsm:AddState(aState)

fsm:AddState(bState)

fsm:AddInitState(aState)

for i = 1, 10 do

    if i == 5 then

        fsm:Switch("bState")

    end

    fsm.curState:OnUpdate()

end

输出

aState:OnUpdate()

aState:OnUpdate()

aState:OnUpdate()

aState:OnUpdate()

aState:OnUpdate()

aState:OnLeave()

bState:OnEnter()

bState:OnUpdate()

bState:OnUpdate()

bState:OnUpdate()

bState:OnUpdate()

bState:OnUpdate()

Lua中使用状态机FSM简单例子的相关教程结束。