状态机示例
回答
您可以将每个用户界面视为一台大型机器。来自UI的每个事件(例如按钮点击,菜单选择等)驱动到另一个状态的转换,这可能意味着新的页面。
另一种情况是订购。新订单(新状态)可以取消或修改,但不予退款。但是,一旦你已经完成了它,它不能被取消,但它可能会被退还。
随机数发生器可以以某种方式被认为是一个状态机。您有一组输入,如左移,加常数,乘以常数等。状态是实际的当前随机值。由于这种随机数的数量是有限的,因此可以认为它是某种有限状态机。
您的操作系统内核调度程序/调度程序是一个状态机。线程具有状态 - 正在运行,准备就绪,睡眠,eventWaiting,暂停,终止。事件是来自IO设备驱动程序的硬件中断和来自运行线程的软件中断。
显示典型导航路径的网站设计(类似于@ duffymo的答案)。下面是一个不完整的例子(由 “UML和模式应用” 的启发(Craig Larman与)):
对于状态机的一些例子(在Umple表示)请参见:
船闸软件: http://cruise.eecs.uottawa.ca/umpleonline/?example=CanalLockStateMachine&diagramtype=state
电信呼叫处理: http://cruise.eecs.uottawa.ca/umpleonline/?example=Phone&diagramtype=state
车库门软件: http://cruise.eecs.uottawa.ca/umpleonline/?example=GarageDoor&diagramtype=state
预订在航空公司预定系统: http://cruise.eecs.uottawa.ca/umpleonline/?example=Booking&diagramtype=state
OpenGL库是一个状态机。它保持一个根据对库函数的调用而改变的状态。你可以在这里看到它:http://www.cs.tufts.edu/research/graphics/resources/OpenGL/OpenGL.htm
状态机可以使用的另一个范围是视频游戏。设想一个相对聪明的敌人。这个敌人将有几种状态:攻击,隐藏,死亡,跑步等。这可以由国家和事件来控制。当我编写一个视频游戏作为我的学位项目时,我使用了两个状态机:一个用于游戏流程(演示屏幕,游戏,选项等),另一个用于游戏本身(提问,掷骰子,移动玩家等)
这里是基本的FSM的玩具控制台应用示例。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
// DESC: QAD-FSM (Quick And Dirty Finite State Machine)
//
// Notes: In its simplest form a state machine is
// • A set of states
// • A set of events
// • A set of transitions that define
// the next state given the current state and event.
// • A method of tracking current state
//
// Example:
//
// I want to create a different kind of door lock that
// has the following states:
//
// 1. LBS - Locked_Both_Sides
// 2. UBS - Unlocked_Both_Sides
// 3. LFO - Locked_From_Outside
//
// and has the following events:
//
// 1. OKT - Outside Key Turn
// 2. IKT - Inside Key Turn
//
// Transistions will be as follows:
//
// CurrState Event NextState Desc
// ========================================================
// LBS OKT UBS When both sides locked, outside key turn unlocks both sides
// LBS IKT LFO When both sides locked, inside key turn unlocks inside
// UBS OKT LFO When both sides unlocked, outside key turn locks outside
// UBS IKT LBS When both sides unlocked, inside key turn locks both sides
// LFO OKT UBS When only outside locked, outside key turn unlocks outside
// LFO IKT LBS When only outside locked, inside key turn locks both sides.
namespace FSM
{
// The FSM states
enum State
{
LBS,
UBS,
LFO
}
// The FSM events
enum Event
{
IKT,
OKT
}
class Transition
{
public State currState { get; set; }
public Event evnt { get; set; }
public State nextState { get; set; }
}
class Program
{
static void Main(string[] args)
{
var fsm = new FSM();
System.Console.WriteLine("Current State: " + fsm.StateDesc[fsm.CurrentState]);
string input = "";
while (input != "x")
{
System.Console.Write("Enter key turn [IKT, OKT] or x to exit: ");
input = System.Console.ReadLine();
if (input == "x") break;
Event evnt;
if (!Enum.TryParse(input, out evnt))
{
System.Console.WriteLine("Invalid input: " + input + ", enter one of [IKT,OKT,x]");
continue;
}
fsm.ChangeState(evnt);
System.Console.WriteLine("New State: " + fsm.StateDesc[fsm.CurrentState]);
}
System.Console.WriteLine("");
System.Console.WriteLine("History");
System.Console.WriteLine("===============================================");
System.Console.WriteLine("CurrState(Event) => NextState");
System.Console.WriteLine("===============================================");
fsm.hist
.Select(h => h.currState.ToString() + "(" + h.evnt.ToString() + ") => " + h.nextState.ToString())
.ToList()
.ForEach(h => System.Console.WriteLine(h));
}
}
class FSM
{
public Dictionary<State, String> StateDesc = new Dictionary<State, String>()
{
{State.LBS, "Both Sides Locked"},
{State.LFO, "Locked From Outside"},
{State.UBS, "Both Sides Unlocked"}
};
public List<Transition> hist = new List<Transition>();
// Create FSM transitions.
List<Transition> trans = new List<Transition>
{
new Transition() { currState = State.LBS, evnt = Event.OKT, nextState = State.UBS },
new Transition() { currState = State.LBS, evnt = Event.IKT, nextState = State.LFO },
new Transition() { currState = State.UBS, evnt = Event.OKT, nextState = State.LFO },
new Transition() { currState = State.UBS, evnt = Event.IKT, nextState = State.LBS },
new Transition() { currState = State.LFO, evnt = Event.OKT, nextState = State.UBS },
new Transition() { currState = State.LFO, evnt = Event.IKT, nextState = State.LBS },
};
public State CurrentState { get { var lt = hist.FirstOrDefault(); return lt == null ? State.UBS : lt.nextState; } }
public State? ChangeState(Event evnt)
{
var t = trans.Find(r => r.currState == CurrentState && r.evnt == evnt);
if (t == null) return null; // If you don't create transitions that cover all combinations this could happen.
hist.Insert(0, t);
return t.nextState;
}
}
}
- 1. HWUT状态机步行者示例
- 2. 示例分机Js状态提供?
- 3. 状态机表示
- 4. React无状态示例
- 5. 用例,类和状态图示例
- 6. 状态机运行完成范例
- 7. 状态机和状态图表示相同吗?
- 8. ObjectOutputStream状态机?
- 9. 在状态机
- 10. VHDL状态机
- 11. 状态机,
- 12. Android状态机
- 13. “实例显示状态”没有编译
- 14. 显示在相机imagePicker状态栏
- 15. 将有限状态机表示为RDF?
- 16. Ruby中的动态状态机?状态机必须是类吗?
- 17. UML状态机子状态转换
- 18. Rails cancan和状态机 - 授权状态
- 19. 无状态自动推进状态机
- 20. 有限状态机过度状态
- 21. VHDL状态机正在跳过状态
- 22. 流星状态机
- 23. 状态机问题
- 24. 状态机实现
- 25. 状态机导轨
- 26. 改善状态机
- 27. 有限状态机
- 28. 状态机执行
- 29. GKEntity和状态机
- 30. 状态机问题
请参阅http://stackoverflow.com/questions/255797/uses-for-state-machines。虽然不确定,但并不完全重复 – CharlesB 2012-04-20 20:15:49