Unity3D有限状态机（FSM）学习笔记【7】使用实例

本系列笔记转载自游戏蛮牛专栏作家Jackel的论坛文章，详细介绍了FSM的创建与使用，特与众分享。链接：http://www.manew.com/thread-37136-1-1.html

一、实例图例

该实例主要是按钮状态的转换。

给大家解析一下，程序运行首先进入主菜单，里面有三个按钮，开始游戏，音量，退出游戏。先从第一个说起，如果是开始游戏，它会进入到下一个界面游戏界面，游戏界面有个返回主菜单功能。二者可以互相切换。接下来是音量按钮，整个按钮是调节音量的，调节好了后，点确认和取消都是返回主菜单。二者之间互相切换，最后一个是退出游戏，会进入是否退出界面，如果否，返回主界面，如果是真正的关闭游戏。我们就把这个简单的功能用我们的有限状态机实现一下：

二、文件结构

左图是有限状态机的代码，共5个，右侧是实例的代码，共6个。下面给出有图的6个文件源码：

一、代码

1、AudioMenuUI

using System.Collections;public class AudioMenuUI : MenuUI, IState{public void OnEnter( string nextState ){}public void OnExit( string nextState ){}public void OnUpdate(){}public override void DoGUI(){if( GUILayout.Button( "Back to menu", GUILayout.Width( Screen.width ), GUILayout.Height( Screen.height / 2 ))){TestUIState.Events.Trigger( "BackToMenu" );}//if( GUILayout.Button( "CloseAudio", GUILayout.Width( Screen.width ), GUILayout.Height( Screen.height / 2 )))//{//TestUIState.Events.Trigger( "CancelQuit" );//}}}

2、MainGame

using UnityEngine;using System.Collections;public class MainGame : MenuUI, IState{protected FiniteStateMachine FSM;protected float Score = 0f;public MainGame( FiniteStateMachine parentMachine ){FSM = parentMachine;}public void OnEnter( string prevState ){Score = 0f;}public void OnExit( string nextState ){}public void OnUpdate(){}public override void DoGUI(){if( GUILayout.Button( "Quit / Back To Menu", GUILayout.Width( Screen.width ))){FSM.Pop();}GUILayout.Space( 25 );GUILayout.Label( "The waiting game!" );GUILayout.Space( 25 );GUILayout.Label( "CurrentScore: " + System.Convert.ToInt32( Score ));Score += Time.deltaTime;}}

3、MainMenuUI

using UnityEngine;using System.Collections;public class MainMenuUI : MenuUI, IState{public void OnEnter( string prevState ){}public void OnExit( string nextState ){}public void OnUpdate(){}public override void DoGUI(){if( GUILayout.Button( "Play Game", GUILayout.Width( Screen.width ), GUILayout.Height( Screen.height / 3 ))){TestUIState.Events.Trigger( "OpenMainGame" );}if( GUILayout.Button( "Audio Menu", GUILayout.Width( Screen.width ), GUILayout.Height( Screen.height / 3 ))){TestUIState.Events.Trigger( "OpenAudioMenu" );}if( GUILayout.Button( "Quit Game", GUILayout.Width( Screen.width ), GUILayout.Height( Screen.height / 3 ))){TestUIState.Events.Trigger( "QuitGame" );}}}

4、MenuUI

using UnityEngine;using System.Collections;public class MenuUI{public virtual void DoGUI(){}}

5、QuitGameUI

using UnityEngine;using System.Collections;public class QuitGameUI : MenuUI, IState{public void OnEnter( string prevState ){}public void OnExit( string nextState ){}public void OnUpdate(){}public override void DoGUI(){GUILayout.BeginHorizontal();if( GUILayout.Button( "Confirm", GUILayout.Width( Screen.width / 2 ), GUILayout.Height( Screen.height ))){TestUIState.Events.Trigger( "ConfirmQuit" );}if( GUILayout.Button( "Cancel", GUILayout.Width( Screen.width / 2 ), GUILayout.Height( Screen.height ))){TestUIState.Events.Trigger( "CancelQuit" );}GUILayout.EndHorizontal();}}

6、TestUIState

using UnityEngine;using System.Collections;public class TestUIState : MonoBehaviour {public static EventSystem.Dispatcher Events = new EventSystem.Dispatcher();public FiniteStateMachine FSM = new FiniteStateMachine();void Awake(){FSM.Register( "MainMenu", new MainMenuUI());FSM.Register( "AudioMenu", new AudioMenuUI());FSM.Register( "MainGame", new MainGame( FSM ));FSM.Register( "QuitGame", new QuitGameUI());FSM.EntryPoint( "MainMenu" );FSM.State( "MainMenu" ).On( "OPEN_AUDIO" ).Enter( "AudioMenu" ).On( "PLAY_GAME" ).Push( "MainGame" ).On( "QUIT_GAME" ).Enter( "QuitGame" );FSM.State( "QuitGame" ).On( "PROCESS_QUIT", delegate( bool sure ){if( sure ){gameObject.GetComponent< TestUIState>().enabled = false;Camera.main.backgroundColor = Color.black;}else{FSM.Enter( "MainMenu" );}} );FSM.State( "AudioMenu" ).On( "BACK_TO_MENU" ).Enter( "MainMenu" );Events.On( "OpenMainGame", delegate() {FSM.CurrentState.Trigger( "PLAY_GAME" );});Events.On( "OpenAudioMenu", delegate() {FSM.CurrentState.Trigger( "OPEN_AUDIO" );});Events.On( "QuitGame", delegate() {FSM.CurrentState.Trigger( "QUIT_GAME" );});Events.On( "ConfirmQuit", delegate() {FSM.CurrentState.Trigger( "PROCESS_QUIT", true );});Events.On( "CancelQuit", delegate() {FSM.CurrentState.Trigger( "PROCESS_QUIT", false );});Events.On( "BackToMenu", delegate() {FSM.CurrentState.Trigger( "BACK_TO_MENU", false );});}void Update(){FSM.Update();}void OnGUI(){if( FSM.CurrentState == null ){return;}MenuUI ui = (MenuUI)FSM.CurrentState.StateObject;ui.DoGUI();}}

二、使用

只需把TestUIState挂在场景的一个对象中即可。

代码：http://pan.baidu.com/s/1c0x1dMK