PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例

PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例_第1张图片
运行实例演示.png

前言:

1.关于PureMVC:

MVC框架在很多项目当中拥有广泛的应用,很多时候做项目前人开坑开了一半就消失了,后人为了填补各种的坑就遭殃的不得了。嘛,程序猿大家都不喜欢像文案策划一样组织文字写东西,也不喜欢看别人留下不清不楚的文档,还不如看代码来得实在。刚开始新人看代码是看得头晕,因为这样那样的东西不一定能完全猜得透。而老人家就算有经验和阅历,也没有这么多的体力去看一个庞大而又复杂的糟糕项目。因为这种需求,Unity3D的程序猿就统一组织起来,想做一个完整规范的程序框架,而这时,PureMVC就诞生了。我个人喜欢PureMVC的原因也很简单,因为它简单粗暴,和Unity3D之间没有依赖性,加上又开源,真的遇到Bug能拿到源代码来调试也是很容易执行的。Unity3D应用商店还有一个同类产品叫uFrame Game Framework,它对Unity版本有着依赖,拖视图虽然方便,但是一旦出bug真的改得够呛的,所以不推荐使用它。下文便是使用PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例。

2.通过MVC模式在Unity项目当中应用的特别提醒:

(1)Unity3D是基于组件设计的,如果没有好的规划,组件之间会产生复杂的调用关系,导致组件之间复杂的依赖,从而破坏了整个系统结构,因此需要设计时确定组件的层次关系,确保依赖关系只存在于下层对上层。而这个是业务逻辑设计问题,PureMVC帮不了你。
(2)仅仅用上MVC,解决不了什么问题,或许解决了1%,剩下的99%就被挪到了MVC的C里,当你庆祝MVC竣工时,99%的问题在那里默默的微笑的看着你。(话说以前写PHP的CI框架时候,一堆东西扔到XxxAction.Class.php里面,发现和摆的乱七八糟的架构没区别,只是大家都习惯了这套框架的规矩,看代码找某个东西稍微好找而已,本质上还是考验基本功和对项目的熟悉程度的,23333)

3.PureMVC通过4种pattern实现隔离变化:

(1)facade非常适合将UI界面对游戏数据的依赖解耦,将UI操作数据的请求封装在facade 接口里面,同时数据变化对UI的影响可以通过notification事件通知来实现,该模式应用得非常常见。
(2)command模式统一对对象的操作,将键盘输入,网络输入输出统一成command来操控游戏对象。
(3)proxy维护数据,提供某块数据统一的初始化,访问和修改接口。
(4)mediator没怎么用过,我们的游戏中的UI界面每次变化一般都是整体更新的,不常用局部更新。
以上4中pattern请务必牢牢记住,请务必牢牢记住,请务必牢牢记住。重要的事情要说3便。

4.PureMVC的流程示意图

(1)在puremvc中,model/view/controller统一是由Facade类的单件实例来统筹管理的。
(2)PureMVC的基本流程:启动PureMVC—>建立Mediator来操作视觉元素(按钮与文本框)—>点击按钮发送Notification->文本框接收Notification改变内容。
(3)大致流程可理解为:通过Facade类的单件实例(即:统一的门面) 启动 puremvc环境,启动同时注册Command对象(相当于asp.net mvc中的controller),然后Command通过与之关联的facade(即前面的单件实例)来注册Mediator(中介者:用于把View与Command联系起来)。
(4)当UI界面(即View)上有动静时(比如按钮点击了之类),与之关联的Mediator(中介者)会发送通知给facade,然后facade会调用command对象执行相关的处理。(即:消息响应)


PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例_第2张图片
PureMVC示意图.png

一.引入PureMVC的插件

1.下载PureMVC

请访问地址
https://github.com/PureMVC/puremvc-csharp-standard-framework/wiki

安装

2.把PureMVC.DotNET.35.dll放到Plugins里面就好了。

QA

3.这里有一个很简单的基本案例可以参考一下
http://www.open-open.com/lib/view/open1452657515480.html

二.动手配置文件

1.需要完成的实例如下:

PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例_第3张图片
实现的界面效果.png

2.具体实现的目标:

(1)在Scripts文件夹下,分别设置模型、视图、控制器对应的文件夹Model、View、Controller,分别放置处理数据模型的脚本、处理显示视图的脚本、处理逻辑控制的脚本。
(2)如界面,一个Unity3D和UGUI制作的简单员工管理系统,Employee Admin,其中员工界面Users显示有哪些员工在登记范围内,而New和Delete分别是添加和删除某个员工的信息。然后下面的员工信息界面User Profile则是对员工信息的一个具体编辑和修正。

三.主要实现步骤

1.启动文件AppFacade.cs 作为PureMVC框架的入口文件。

using UnityEngine;
using System.Collections;
using PureMVC.Patterns;
using PureMVC.Interfaces;

//Facade模式的单例
public class ApplicationFacade : Facade
{
    //实例化函数,保证单例模式(Singleton)运行该函数
    public new static IFacade Instance
    {
        get
        {
            if(m_instance == null)
            {
                lock(m_staticSyncRoot)
                {
                    if (m_instance == null)
                    {
                        Debug.Log("ApplicationFacade");
                        m_instance = new ApplicationFacade();
                    }
                }
            }
            return m_instance;
        }
    }
    //启动PureMVC的入口函数
    public void Startup(MainUI mainUI)
    {
        Debug.Log("Startup() to SendNotification.");
        SendNotification(EventsEnum.STARTUP, mainUI);
    }
    //该类的构造器
    protected ApplicationFacade()
    {

    }
    //设置静态
    static ApplicationFacade()
    {

    }
    //初始化控制器函数
    protected override void InitializeController()
    {
        Debug.Log("InitializeController()");
        base.InitializeController();
        RegisterCommand(EventsEnum.STARTUP, typeof(StartupCommand));
        RegisterCommand(EventsEnum.DELETE_USER, typeof(DeleteUserCommand));
    }
}

2.对PureMVC需要处理的事件用EventsEnum.cs存放

using UnityEngine;
using System.Collections;

//处理事件的枚举
public class EventsEnum
{
    public const string STARTUP = "startup";//启动事件

    public const string NEW_USER = "newUser";//新建用户
    public const string DELETE_USER = "deleteUser";//删除用户
    public const string CANCEL_SELECTED = "cancelSelected";//取消选择

    public const string USER_SELECTED = "userSelected";//选择用户
    public const string USER_ADDED = "userAdded";//添加用户
    public const string USER_UPDATED = "userUpdated";//更新用户
    public const string USER_DELETED = "userDeleted";//删除用户

    public const string ADD_ROLE = "addRole";//添加角色
    public const string ADD_ROLE_RESULT = "addRoleResult";//查询添加角色的结果
}

3.然后在Unity的场景中创建一个MainUI.cs文件,挂在需要启动PureMVC的组件上。就可以启动了。

using UnityEngine;
using System.Collections;

//处理该UI场景的入口
public class MainUI : MonoBehaviour
{
    public UserList userList;
    public UserForm userForm;
    //启动函数
    void Awake()
    {
        //启动PureMVC程序,执行StartUP()方法
        ApplicationFacade facade = ApplicationFacade.Instance as ApplicationFacade;
        facade.Startup(this);
    }
}

4.对Controller部分进行处理

然后我们对执行逻辑的处理事件进行补充。新建一个文件夹Controller,暂时先放置StartupCommand.cs和DeleteUserCommand.cs。处理上述所说的逻辑事件
首先,处理启动事件

using UnityEngine;
using System.Collections;
using PureMVC.Patterns;
using PureMVC.Interfaces;

//启动事件
public class StartupCommand : SimpleCommand, ICommand
{
    //复写原有的Execute执行函数
    public override void Execute(INotification notification)
    {
        //注册统一的数据接口UserProxy,给其他事件处理
        Debug.Log("StartupCommand.Execute()");
        Facade.RegisterProxy(new UserProxy());

        //注册局部界面Mediator,给其他事件处理
        MainUI mainUI = notification.Body as MainUI;
        Facade.RegisterMediator(new UserListMediator(mainUI.userList));
        Facade.RegisterMediator(new UserFormMediator(mainUI.userForm));
    }
}

其次,处理删除用户事件

using PureMVC.Patterns;
using PureMVC.Interfaces;

//删除用户事件
public class DeleteUserCommand : SimpleCommand, ICommand
{
   //复写原有的Execute执行函数
    public override void Execute(INotification notification)
    {
        //获取要删除的对象user
        UserVO user = (UserVO)notification.Body;
        //获取处理数据操作的userProxy
        UserProxy userProxy = (UserProxy)Facade.RetrieveProxy(UserProxy.NAME);

        //操作数据,删除user
        userProxy.DeleteItem(user);
        //删除完毕,广播USER_DELETED进行通知
        SendNotification(EventsEnum.USER_DELETED);
    }
}

5.对Model部分进行处理

然后是对Model模型数据的定义哈,首先要记录的信息用UserVO来表示

using UnityEngine;
using System.Collections;
//显示用的数据信息UserViewObject
public class UserVO
{
    //用户名
    public string UserName
    {
        get { return m_userName; }
    }
    private string m_userName = "";
    //名字
    public string FirstName
    {
        get { return m_firstName; }
    }
    private string m_firstName = "";
    //姓氏
    public string LastName
    {
        get { return m_lastName; }
    }
    private string m_lastName = "";
    //邮箱
    public string Email
    {
        get { return m_email; }
    }
    private string m_email = "";
    //密码
    public string Password
    {
        get { return m_password; }
    }
    private string m_password = "";
    //部门
    public string Department
    {
        get { return m_department; }
    }
    private string m_department = "";
    //是否合法
    public bool IsValid
    {
        get
        {
            return !string.IsNullOrEmpty(UserName) && !string.IsNullOrEmpty(Password);
        }
    }
    //合并名字
    public string GivenName
    {
        get { return LastName + ", " + FirstName; }
    }
    //构造器
    public UserVO()
    {
    }
    //构造函数
    public UserVO(string uname, string fname, string lname, string email, string password, string department)
    {
        if (uname != null) m_userName = uname;
        if (fname != null) m_firstName = fname;
        if (lname != null) m_lastName = lname;
        if (email != null) m_email = email;
        if (password != null) m_password = password;
        if (department != null) m_department = department;
    }
}

接着对操作数据的UserProxy进行补充

using UnityEngine;
using System.Collections.Generic;
using PureMVC.Patterns;
using PureMVC.Interfaces;

//数据操作
public class UserProxy : Proxy, IProxy
{
    public new const string NAME = "UserProxy";

    //返回数据操作类
    public IList Users
    {
        get { return (IList) base.Data; }
    }

    //构造函数,添加几条数据进去先
    public UserProxy():base(NAME, new List())
    {
        Debug.Log("UserProxy()");
        //添加几条测试用的数据        
        AddItem(new UserVO("lstooge", "Larry", "Stooge", "[email protected]", "ijk456", "ACCT"));
        AddItem(new UserVO("cstooge", "Curly", "Stooge", "[email protected]", "xyz987", "SALES"));
        AddItem(new UserVO("mstooge", "Moe", "Stooge", "[email protected]", "abc123", "PLANT"));
        AddItem(new UserVO("lzh", "abc", "def", "[email protected]", "abc123", "IT"));
    }

    //添加数据的方法
    public void AddItem(UserVO user)
    {
        Users.Add(user);
    }

    //更新数据的方法
    public void UpdateItem(UserVO user)
    {
        for (int i = 0; i < Users.Count; i++)
        {
            if (Users[i].UserName.Equals(user.UserName))
            {
                Users[i] = user;
                break;
            }
        }
    }

    //删除数据的方法
    public void DeleteItem(UserVO user)
    {
        for (int i = 0; i < Users.Count; i++)
        {
            if (Users[i].UserName.Equals(user.UserName))
            {
                Users.RemoveAt(i);
                break;
            }
        }
    }
}

6.接下来对VIew部分进行实现

显示用户界面列表的UserList和填写用户具体信息的UserForm
列表单条数据部分

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

//UserList列表当中单条数据信息
public class UserList_Item : MonoBehaviour
{
    //定义UI组件
    public Text txt_userName;//用户名文本框
    public Text txt_firstName;//名字文本框
    public Text txt_lastName;//姓氏文本框
    public Text txt_email;//邮件文本框
    public Text txt_department;//部门文本框

    //定义User信息类
    public UserVO userData;

    //更新User类
    public void UpdateData(UserVO data)
    {
        //获取需要更改的User信息
        this.userData = data;

        //更改UI的文字信息
        txt_userName.text = data.UserName;
        txt_firstName.text = data.FirstName;
        txt_lastName.text = data.LastName;
        txt_email.text = data.Email;
        txt_department.text = data.Department;
    }
}

用户列表部分

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

//UserList用户界面列表部分
public class UserList : MonoBehaviour
{
    //定义UI组件
    public Text txt_userCount;//用户列表文本框
    public UGUI_MyToggleGroup myToggleGroup;//用户列表滑动条
    public Button btn_New;//新建按钮
    public Button btn_Delete;//删除按钮
    public UserList_Item itemPrefab;//单个列表文件的预置体
    List itemList = new List();//临时存列表

    //定义事件操作
    public System.Action NewUser;//添加用户事件
    public System.Action DeleteUser;//删除用户事件
    public System.Action SelectUser;//选择用户事件

    //定义数据
    public UserVO SelectedUserData;//列表中选择好的用户
    private IList m_currentUsers;//当前选择的用户

    //开始函数
    void Start ()
    {
        itemPrefab.gameObject.SetActive(false);

        myToggleGroup.onToggleChange.AddListener(onSelectUserItem);
        btn_New.onClick.AddListener(onClick_btn_New);
        btn_Delete.onClick.AddListener(onClick_btn_Delete);

        UpdateButtons();
    }
    //加载用户
    public void LoadUsers(IList list)
    {
        m_currentUsers = list;
        RefreshUI(list);
    }
    //点击新建
    void onClick_btn_New()
    {
        if (NewUser != null) NewUser();
    }
    //点击删除
    void onClick_btn_Delete()
    {
        if (DeleteUser != null) DeleteUser();
    }
    //选择物体
    void onSelectUserItem(Toggle itemToggle)
    {
        if (itemToggle == null)
        {
            return;
        }

        UserList_Item item = itemToggle.GetComponent();
        this.SelectedUserData = item.userData;
        UpdateButtons();
        if (SelectUser != null) SelectUser();

    }
    //取消选择
    public void Deselect()
    {
        myToggleGroup.toggleGroup.SetAllTogglesOff();
        this.SelectedUserData = null;
        UpdateButtons();
    }
    //刷新UI
    void RefreshUI(IList datas)
    {
        ClearItems();
        foreach (var data in datas)
        {
            UserList_Item item = CreateItem();
            item.UpdateData(data);
            itemList.Add(item);
        }
        txt_userCount.text = datas.Count.ToString();
    }
    //新建列表项目
    UserList_Item CreateItem()
    {
        UserList_Item item = GameObject.Instantiate(itemPrefab);
        item.transform.SetParent(itemPrefab.transform.parent);
        item.gameObject.SetActive(true);
        item.transform.localScale = Vector3.one;
        item.transform.localPosition = Vector3.zero;

        return item;
    }
    //清空列表
    void ClearItems()
    {
        foreach(var item in itemList)
        {
            Destroy(item.gameObject);
        }
        itemList.Clear();
    }
    //更新按钮
    private void UpdateButtons()
    {
        btn_Delete.interactable = (SelectedUserData != null);
    }
}

用户个人信息部分

using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using UnityEngine.EventSystems;

//用户个人信息表单模式?编辑:新增
public enum UserFormMode
{
    ADD,
    EDIT,
}
//用户个人信息表单
public class UserForm : MonoBehaviour
{
    //UI项的定义
    public InputField txt_firstName;
    public InputField txt_lastName;
    public InputField txt_email;
    public InputField txt_userName;
    public InputField txt_password;
    public InputField txt_confirmPassword;
    public InputField txt_department;
    public Button btn_updateUser;
    public Button btn_cancel;

    //其他
    public System.Action AddUser;
    public System.Action UpdateUser;
    public System.Action CancelUser;

    //用户信息获取
    public UserVO User
    {
        get { return m_user; }
    }
    private UserVO m_user;

    //用户信息表单
    public UserFormMode Mode
    {
        get { return m_mode; }
    }
    private UserFormMode m_mode = UserFormMode.ADD;

    //开始
    void Start ()
    {
        //设置UI
        btn_updateUser.onClick.AddListener(btn_updateUser_Click);
        btn_cancel.onClick.AddListener(btn_cancel_Click);

        txt_userName.onValueChange.AddListener(InputField_onValueChange);
        txt_password.onValueChange.AddListener(InputField_onValueChange);
        txt_confirmPassword.onValueChange.AddListener(InputField_onValueChange);

        UpdateButtons();
    }

    //显示当前用户信息
    public void ShowUser(UserVO user, UserFormMode mode)
    {
        m_mode = mode;
        if (user == null)
        {
            ClearForm();
        }
        else
        {
            m_user = user;
            txt_firstName.text = user.FirstName;
            txt_lastName.text = user.LastName;
            txt_email.text = user.Email;
            txt_userName.text = user.UserName;
            txt_password.text = txt_confirmPassword.text = user != null ? user.Password : "";
            txt_department.text = user.Department;
            //txt_firstName.ActivateInputField();
            EventSystem.current.SetSelectedGameObject(txt_firstName.gameObject);
            //txt_firstName.MoveTextEnd(false);
            txt_firstName.caretPosition = txt_firstName.text.Length - 1;
            UpdateButtons();
        }
    }

    //更新按钮
    private void UpdateButtons()
    {
        if (btn_updateUser != null)
        {
            btn_updateUser.interactable = (txt_firstName.text.Length > 0 && txt_password.text.Length > 0 && txt_password.text.Equals(txt_confirmPassword.text));
        }
    }

    //清空表单
    public void ClearForm()
    {
        m_user = null;
        txt_firstName.text = txt_lastName.text = txt_email.text = txt_userName.text = "";
        txt_password.text = txt_confirmPassword.text = "";
        txt_department.text = "";
        UpdateButtons();
    }

    //更新用户信息
    void btn_updateUser_Click()
    {
        m_user = new UserVO(
            txt_userName.text, txt_firstName.text, 
            txt_lastName.text, txt_email.text, 
            txt_password.text, txt_department.text);

        if (m_user.IsValid)
        {
            if (m_mode == UserFormMode.ADD)
            {
                if (AddUser != null) AddUser();
            }
            else
            {
                if (UpdateUser != null) UpdateUser();
            }
        }
    }

    //取消信息
    void btn_cancel_Click()
    {
        if (CancelUser != null) CancelUser();
    }

    //输入
    void InputField_onValueChange(string value)
    {
        UpdateButtons();
    }
}

最后,对局部更新UI的行为进行完善Mediator

using UnityEngine;
using System.Collections;
using PureMVC.Patterns;
using PureMVC.Interfaces;
using System.Collections.Generic;
//更新UserList部分
public class UserListMediator : Mediator, IMediator
{
    private UserProxy userProxy;

    public new const string NAME = "UserListMediator";

    private UserList View
    {
        get { return (UserList)ViewComponent; }
    }

    public UserListMediator(UserList userList)
            : base(NAME, userList)
    {
        Debug.Log("UserListMediator()");
        userList.NewUser += userList_NewUser;
        userList.DeleteUser += userList_DeleteUser;
        userList.SelectUser += userList_SelectUser;
    }

    public override void OnRegister()
    {
        Debug.Log("UserListMediator.OnRegister()");
        base.OnRegister();
        userProxy = Facade.RetrieveProxy(UserProxy.NAME) as UserProxy;
        View.LoadUsers(userProxy.Users);
    }

    void userList_NewUser()
    {
        UserVO user = new UserVO();
        SendNotification(EventsEnum.NEW_USER, user);
    }

    void userList_DeleteUser()
    {
        SendNotification(EventsEnum.DELETE_USER, View.SelectedUserData);
    }

    void userList_SelectUser()
    {
        SendNotification(EventsEnum.USER_SELECTED, View.SelectedUserData);
    }

    public override IList ListNotificationInterests()
    {
        IList list = new List();
        list.Add(EventsEnum.USER_DELETED);
        list.Add(EventsEnum.CANCEL_SELECTED);
        list.Add(EventsEnum.USER_ADDED);
        list.Add(EventsEnum.USER_UPDATED);
        return list;
    }

    public override void HandleNotification(INotification notification)
    {
        switch(notification.Name)
        {
            case EventsEnum.USER_DELETED:
                View.Deselect();
                View.LoadUsers(userProxy.Users);
                break;
            case EventsEnum.CANCEL_SELECTED:
                View.Deselect();
                break;
            case EventsEnum.USER_ADDED:
                View.Deselect();
                View.LoadUsers(userProxy.Users);
                break;
            case EventsEnum.USER_UPDATED:
                View.Deselect();
                View.LoadUsers(userProxy.Users);
                break;
        }
    }
}

using UnityEngine;
using System.Collections;
using PureMVC.Patterns;
using PureMVC.Interfaces;
using System.Collections.Generic;
//更新UserForm部分
public class UserFormMediator : Mediator, IMediator
{
    private UserProxy userProxy;

    public new const string NAME = "UserFormMediator";

    private UserForm View
    {
        get { return (UserForm)ViewComponent; }
    }

    public UserFormMediator(UserForm viewComponent)
        : base(NAME, viewComponent)
    {
        Debug.Log("UserFormMediator()");

        View.AddUser += UserForm_AddUser;
        View.UpdateUser += UserForm_UpdateUser;
        View.CancelUser += UserForm_CancelUser;
    }

    public override void OnRegister()
    {
        base.OnRegister();
        userProxy = Facade.RetrieveProxy(UserProxy.NAME) as UserProxy;
    }

    void UserForm_AddUser()
    {
        UserVO user = View.User;
        userProxy.AddItem(user);
        SendNotification(EventsEnum.USER_ADDED, user);
        View.ClearForm();
    }

    void UserForm_UpdateUser()
    {
        UserVO user = View.User;
        userProxy.UpdateItem(user);
        SendNotification(EventsEnum.USER_UPDATED, user);
        View.ClearForm();
    }

    void UserForm_CancelUser()
    {
        SendNotification(EventsEnum.CANCEL_SELECTED);
        View.ClearForm();
    }

    public override IList ListNotificationInterests()
    {
        IList list = new List();
        list.Add(EventsEnum.NEW_USER);
        list.Add(EventsEnum.USER_DELETED);
        list.Add(EventsEnum.USER_SELECTED);
        return list;
    }

    public override void HandleNotification(INotification note)
    {
        UserVO user;
        switch (note.Name)
        {
            case EventsEnum.NEW_USER:
                user = (UserVO)note.Body;
                View.ShowUser(user, UserFormMode.ADD);
                break;

            case EventsEnum.USER_DELETED:
                View.ClearForm();
                break;

            case EventsEnum.USER_SELECTED:
                user = (UserVO)note.Body;
                View.ShowUser(user, UserFormMode.EDIT);
                break;

        }
    }
}

补充,UI的选择部分

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

[RequireComponent(typeof(Toggle))]
public class UGUI_MyToggle : MonoBehaviour
{    
    [SerializeField]Toggle toggle;
    [SerializeField]UGUI_MyToggleGroup myToggleGroup;

    void Start()
    {
        if (toggle == null) toggle = this.GetComponent();
        if (myToggleGroup == null) myToggleGroup = toggle.group.GetComponent();

        toggle.onValueChanged.AddListener(onToggle);
    }

    void onToggle(bool value)
    {
        if(value)
        {
            myToggleGroup.ChangeToggle(toggle);
        }
    }
}

//[lzh]
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;
using System.Collections;

public class ToggleEvent : UnityEvent { }

[RequireComponent(typeof(ToggleGroup))]
public class UGUI_MyToggleGroup : MonoBehaviour
{
public ToggleGroup toggleGroup;
public ToggleEvent onToggleChange = new ToggleEvent();

void Start()
{
    if (toggleGroup == null) toggleGroup = this.GetComponent();
}

public void ChangeToggle(Toggle toggle)
{
    onToggleChange.Invoke(toggle);
}

}


你可能感兴趣的:(PureMVC和Unity3D的UGUI制作一个简单的员工管理系统实例)