class Program
{
    //1、聲明委托類型
    public delegate void AddDelegate(int a, int b);
    
    //2、委托函數(shù)（方法），參數(shù)需要和委托參數(shù)一致
    public static void Add(int a, int b)
    {
        Console.WriteLine(a + b);
    }
    
    static void Main(string[] args)
    {
        //3、創(chuàng)建委托實(shí)例，將方法名Add作為參數(shù)綁定到該委托實(shí)例，也可以不使用new，直接AddDelegate addDelegate = Add;
        AddDelegate addDelegate = new AddDelegate(Add);
        //4、調(diào)用委托實(shí)例
        addDelegate(1, 2);
        Console.ReadKey();
    }
}

public class Account
{
	private float bank_savings = 1000; // 存款金額
	public event Action OnInsufficientBalance; // 余額不足事件
	
	public void cosume(float money)
	{
		bank_savings -= money;
		if (bank_savings < 100)
		{
			OnInsufficientBalance.InVoke();
		}
	}
}

public class Notify
{
	public static void Email()
    {
		Console.WriteLine("Insufficient Balance");
    }
}



class Program
{
	static void Main(string[] args)
	{
		var account = new Account();
		account.OnInsufficientBalance += Notify.Email;
		
		account.cosume(1000);
	}
}

button1 = new QPushButton("close",this);//創(chuàng)建按鈕，指定父對(duì)象
button2 = new QPushButton("print",this);//創(chuàng)建按鈕，指定父對(duì)象

connect(button1,&QPushButton::clicked,this,&QWidget::close);
connect(button2,&QPushButton::clicked,this,[](){
        qDebug() << "關(guān)閉成功";//打印關(guān)閉成功
    });

#ifndef __UIDELEGATE_H__
#define __UIDELEGATE_H__

#pragma once

namespace DuiLib {

class DUILIB_API CDelegateBase	 
{
public:
    CDelegateBase(void* pObject, void* pFn);
    CDelegateBase(const CDelegateBase& rhs);
    virtual ~CDelegateBase();
    bool Equals(const CDelegateBase& rhs) const;
    bool operator() (void* param);
    virtual CDelegateBase* Copy() const = 0; // add const for gcc

protected:
    void* GetFn();
    void* GetObject();
    virtual bool Invoke(void* param) = 0;

private:
    void* m_pObject;
    void* m_pFn;
};

class CDelegateStatic: public CDelegateBase
{
    typedef bool (*Fn)(void*);
public:
    CDelegateStatic(Fn pFn) : CDelegateBase(NULL, pFn) { } 
    CDelegateStatic(const CDelegateStatic& rhs) : CDelegateBase(rhs) { } 
    virtual CDelegateBase* Copy() const { return new CDelegateStatic(*this); }

protected:
    virtual bool Invoke(void* param)
    {
        Fn pFn = (Fn)GetFn();
        return (*pFn)(param); 
    }
};

template <class O, class T>
class CDelegate : public CDelegateBase
{
    typedef bool (T::* Fn)(void*);
public:
    CDelegate(O* pObj, Fn pFn) : CDelegateBase(pObj, *(void**)&pFn) { }
    CDelegate(const CDelegate& rhs) : CDelegateBase(rhs) { } 
    virtual CDelegateBase* Copy() const { return new CDelegate(*this); }

protected:
    virtual bool Invoke(void* param)
    {
		O* pObject = (O*) GetObject();
		union
		{
			void* ptr;
			Fn fn;
		} func = { GetFn() };
		return (pObject->*func.fn)(param);
    }  

private:
	Fn m_pFn;
};

template <class O, class T>
CDelegate<O, T> MakeDelegate(O* pObject, bool (T::* pFn)(void*))
{
    return CDelegate<O, T>(pObject, pFn);
}

inline CDelegateStatic MakeDelegate(bool (*pFn)(void*))
{
    return CDelegateStatic(pFn); 
}

class DUILIB_API CEventSource
{
    typedef bool (*FnType)(void*);
public:
    ~CEventSource();
    operator bool();
    void operator+= (const CDelegateBase& d); // add const for gcc
    void operator+= (FnType pFn);
    void operator-= (const CDelegateBase& d);
    void operator-= (FnType pFn);
    bool operator() (void* param);

protected:
    CDuiPtrArray m_aDelegates;
};

} // namespace DuiLib

#endif // __UIDELEGATE_H__

#include "StdAfx.h"

namespace DuiLib {

CDelegateBase::CDelegateBase(void* pObject, void* pFn) 
{
    m_pObject = pObject;
    m_pFn = pFn; 
}

CDelegateBase::CDelegateBase(const CDelegateBase& rhs) 
{
    m_pObject = rhs.m_pObject;
    m_pFn = rhs.m_pFn; 
}

CDelegateBase::~CDelegateBase()
{

}

bool CDelegateBase::Equals(const CDelegateBase& rhs) const 
{
    return m_pObject == rhs.m_pObject && m_pFn == rhs.m_pFn; 
}

bool CDelegateBase::operator() (void* param) 
{
    return Invoke(param); 
}

void* CDelegateBase::GetFn() 
{
    return m_pFn; 
}

void* CDelegateBase::GetObject() 
{
    return m_pObject; 
}

CEventSource::~CEventSource()
{
    for( int i = 0; i < m_aDelegates.GetSize(); i++ ) {
        CDelegateBase* pObject = static_cast<CDelegateBase*>(m_aDelegates[i]);
        if( pObject) delete pObject;
    }
}

CEventSource::operator bool()
{
    return m_aDelegates.GetSize() > 0;
}

void CEventSource::operator+= (const CDelegateBase& d)
{ 
    for( int i = 0; i < m_aDelegates.GetSize(); i++ ) {
        CDelegateBase* pObject = static_cast<CDelegateBase*>(m_aDelegates[i]);
        if( pObject && pObject->Equals(d) ) return;
    }

    m_aDelegates.Add(d.Copy());
}

void CEventSource::operator+= (FnType pFn)
{ 
    (*this) += MakeDelegate(pFn);
}

void CEventSource::operator-= (const CDelegateBase& d) 
{
    for( int i = 0; i < m_aDelegates.GetSize(); i++ ) {
        CDelegateBase* pObject = static_cast<CDelegateBase*>(m_aDelegates[i]);
        if( pObject && pObject->Equals(d) ) {
            delete pObject;
            m_aDelegates.Remove(i);
            return;
        }
    }
}
void CEventSource::operator-= (FnType pFn)
{ 
    (*this) -= MakeDelegate(pFn);
}

bool CEventSource::operator() (void* param) 
{
    for( int i = 0; i < m_aDelegates.GetSize(); i++ ) {
        CDelegateBase* pObject = static_cast<CDelegateBase*>(m_aDelegates[i]);
        if( pObject && !(*pObject)(param) ) return false;
    }
    return true;
}

} // namespace DuiLib

#ifndef _EVENT_H_
#define _EVENT_H_

#include <vector>
#include <functional>
#include <type_traits>
#include <memory>
#include <assert.h>


namespace stubbornhuang
{
	// 原型
	template<typename Prototype> class Event;


	// 特例
	template<typename ReturnType, typename ...Args>
	class Event <ReturnType(Args...)>
	{
	private:
		using return_type = ReturnType;
		using function_type = ReturnType(Args...);
		using stl_function_type = std::function<function_type>;
		using pointer = ReturnType(*)(Args...);

	private:
		class EventHandler
		{
		public:
			EventHandler(stl_function_type func)
			{
				assert(func != nullptr);
				m_Handler = func;
			}

			void Invoke(Args ...args)
			{
				if (m_Handler != nullptr)
				{
					m_Handler(args...);
				}
			}

		private:
			stl_function_type m_Handler;
		};

	public:
		void operator += (stl_function_type func)
		{
			std::shared_ptr<EventHandler> pEventHandler = std::make_shared<EventHandler>(func);

			if (pEventHandler != nullptr)
			{
				m_HandlerVector.push_back(std::move(pEventHandler));
			}
		}

		void Connect(stl_function_type func)
		{
			std::shared_ptr<EventHandler> pEventHandler = std::make_shared<EventHandler>(func);

			if (pEventHandler != nullptr)
			{
				m_HandlerVector.push_back(std::move(pEventHandler));
			}
		}

		void operator() (Args ...args)
		{
			for (int i = 0; i < m_HandlerVector.size(); ++i)
			{
				if (m_HandlerVector[i] != nullptr)
				{
					m_HandlerVector[i]->Invoke(args...);
				}
			}
		}

		void Trigger(Args ...args)
		{
			for (int i = 0; i < m_HandlerVector.size(); ++i)
			{
				if (m_HandlerVector[i] != nullptr)
				{
					m_HandlerVector[i]->Invoke(args...);
				}
			}
		}

	private:
		std::vector<std::shared_ptr<EventHandler>> m_HandlerVector;
	};
}


#endif // !_EVENT_H_

#include <iostream>

#include "Event.h"

class Button
{
public:
	Button()
	{

	}

	virtual~Button()
	{

	}

public:
	stubbornhuang::Event<void()> OnClick;
};

void Click()
{
	std::cout << "Button Click" << std::endl;
}


class Example
{
public:
	void Click()
	{
		std::cout << "Example Click" << std::endl;
	}
};

int main()
{
	Button button;

	button.OnClick += Click; // 靜態(tài)函數(shù)做委托函數(shù)

	Example example;
	button.OnClick += std::bind(&Example::Click, example); // 成員函數(shù)做委托函數(shù) 

	button.OnClick += []() { std::cout << "Lambda Click" << std::endl;  }; // 匿名函數(shù)做委托函數(shù)

	button.OnClick();

	return 0;
}