C++ 自定义事件机制2

来源：互联网发布：懒人眼镜淘宝编辑：程序博客网时间：2024/06/14 04:15

可以使用成员函数指针，用到了类模版！

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1、要定义一个事件基类，可以使用它传递不懂类型的参数。

myevent.h

#pragma once#include <iostream>#include <string>using namespace std;class MyEvent{public:MyEvent(string type);~MyEvent();string getType();protected:private:string _type;};

myevent.cpp

#include "myevent.h"MyEvent::MyEvent(string type){_type = type;cout << "MyEvent()" << endl;}MyEvent::~MyEvent(){cout << "~MyEvent()" << endl;}std::string MyEvent::getType(){return _type;}

2、然后要有一个类型和函数指针的模版类。

eventitem.h

#pragma once#include "myevent.h"#include <memory>template <typename T>class EventItem{typedef void(T::*ItemFUN)(MyEvent&);public:EventItem(){cout << "EventItem()" << endl;}~EventItem(){cout << "~EventItem()" << endl;}void (T::*f)(MyEvent&);shared_ptr<T> t;};

3、定义事件收发管理类

eventdispatcher.h

#pragma once#include <unordered_map>#include <string>#include "myevent.h"#include <iostream>#include "eventitem.h"#include <memory>using namespace std;template<typename T>class EventDispatcher{typedef void(T::*EventFun)(MyEvent&);public:static void addEventListener(string type, shared_ptr<T> t, EventFun f);static void dispatchEvent(shared_ptr<MyEvent> sp);static void removeEventListener(string type);static bool hasEventListener(string type);private:static unordered_map<string, shared_ptr<EventItem<T>>> events;};template<typename T>unordered_map<string, shared_ptr<EventItem<T>>> EventDispatcher<T>::events;template<typename T>void EventDispatcher<T>::addEventListener(string type, shared_ptr<T> t, EventFun f){if (!hasEventListener(type)){shared_ptr<EventItem<T>> spItem = make_shared<EventItem<T>>();spItem->t = t;spItem->f = f;events[type] = spItem;}else{cout << "事件 " << type << " 已经定义" << endl;}}template<typename T>void EventDispatcher<T>::dispatchEvent(shared_ptr<MyEvent> sp){string& temp = sp->getType();if (hasEventListener(temp)){shared_ptr<EventItem<T>> spItem = events[temp];((*spItem).t->*(*spItem).f)(*sp);cout << spItem->t->i << endl;}else{cout << "事件 " << temp << " 未定义" << endl;}}template<typename T>void EventDispatcher<T>::removeEventListener(string type){if (hasEventListener(type)){events.erase(type);}else{cout << "事件 " << type << " 未定义" << endl;}}template<typename T>bool EventDispatcher<T>::hasEventListener(string type){if (events[type] != nullptr){return true;}return false;}

至此就可以使用了简单吧~

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使用案例：

main.cpp

#include <iostream>#include "eventdispatcher.h"#include <memory>class Test{public:int i;Test(){cout << "Test()" << endl;}~Test(){cout << "~Test()" << endl;}void test(MyEvent& e){cout << "what the hell!!!" << endl;i++;}protected:private:};void fun(){shared_ptr<Test> pt = make_shared<Test>();pt->i = 10;EventDispatcher<Test>::addEventListener("hello", pt, &Test::test);EventDispatcher<Test>::addEventListener("jj", pt, &Test::test);}void del(){EventDispatcher<Test>::removeEventListener("hello");}int main(){fun();del();system("pause");return 0;}

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