C++: 类单例的宏实现(方便调用)

//=============== Micros ===============

// singleton declare

#define DECLARE_SHARE(ClassName) \

    private:\

        static ClassName* singleInstance;\

    public:\

        static ClassName* shareInstance()\

        {\

            if(NULL == singleInstance) singleInstance = new ClassName();\

            return singleInstance;\

        }\

    private:\

        class CGarbo\

        {\

            public:\

            ~CGarbo()\

            {if( ClassName::singleInstance )delete ClassName::singleInstance;}\

        };\

        static CGarbo Garbo;

//

#define BUILD_SHARE(ClassName)\

    ClassName* ClassName::singleInstance = NULL;

使用方式:

单例类头文件中需要引用包含该宏的头文件,并在声明中使用该宏的 DECLARE_SHARE() 

而类实现中需要在一开始 BUILD_SHARE()

例:

//dlgmain.h

class DlgMain : public QDialog

{

    Q_OBJECT

    DECLARE_SHARE(DlgMain)

public:

    explicit DlgMain(QWidget *parent = 0);

    ~DlgMain();

}

//dlgmain.cpp

#include "dlgmain.h"

BUILD_SHARE(DlgMain)

DlgMain::DlgMain(QWidget *parent) :

    QDialog(parent),

    ui(new Ui::DlgMain)

{

    ui->setupUi(this);

...

}

...