Qt C++ flyweight模式

最新推荐文章于 2025-07-12 14:01:50 发布

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本文介绍了一种使用C++实现的享元模式，通过CFlyWeightFactory工厂类来管理CFlyweightBase及其子类CConcreateFly对象，避免了大量相似对象的重复创建，从而节省内存资源。

flyweight.h

#pragma once

#include <QDebug>

class CFlyweightBase
{
public:
virtual void operate() = 0;
virtual QString getText() const{return m_text;}
protected:
CFlyweightBase(QString text){m_text = text;}
QString m_text;
};

class CConcreateFly : public CFlyweightBase
{
public:
CConcreateFly(QString text):CFlyweightBase(text){}
void operate()
{
qDebug() << m_text;
}
};

class CFlyWeightFactory
{
public:
CFlyWeightFactory(){}
~CFlyWeightFactory()
{
qDeleteAll(m_lst.begin(),m_lst.end());
}

CFlyweightBase* getFlyweight(const QString& text);

private:
QList<CFlyweightBase*> m_lst;
};

flyweight.cpp

#include "flyweight.h"

CFlyweightBase* CFlyWeightFactory::getFlyweight(const QString& text)
{
QListIterator<CFlyweightBase*> iter(m_lst);
while(iter.hasNext())
{
CFlyweightBase* ptr = iter.next();
if (ptr->getText() == text)
{
qDebug() << text << " already exits";
return ptr;
}
}
CFlyweightBase* new_ptr = new CConcreateFly(text);
m_lst.append(new_ptr);
return new_ptr;
}

main.cpp

#include <QApplication>
#include "flyweight.h"

int main(int argc,char **argv)
{
QApplication app(argc,argv);

CFlyWeightFactory *fac = new CFlyWeightFactory;
fac->getFlyweight("hello");
fac->getFlyweight("data");
fac->getFlyweight("hello");

delete fac;
return app.exec();
}