QT信号函数和槽函数的基本代码实现

exampleA.h:

#ifndef EXAMPLEA_H

#define EXAMPLEA_H

#endif // EXAMPLEA_H

#include<QCoreApplication>

class CExampleA:public QObject

{

    Q_OBJECT

public:

    CExampleA(){m_Value=0;}

    void SetValue(int nNewval)

    {

        if(m_Value==nNewval)

        {

            return ;

        }

        m_Value=nNewval;

        emit stateChanged(m_Value);

    }

signals:

    void stateChanged(int nNewVal);

private:

    int m_Value;

};

exampleb.h:

    #ifndef EXAMPLEB_H

    #define EXAMPLEB_H

    #endif // EXAMPLEB_H

    #include<QDebug>

    #include<QCoreApplication>

    class CExampleB:public QObject

    {

        Q_OBJECT

    public:

        CExampleB(){}

    public slots:

        void Function(int nNewValue)

        {

            qDebug()<<"new Values = "<<nNewValue;

        }

    };

main.cpp:

#include<examplea.h>

#include<exampleb.h>

int main()

{

    CExampleA a;

    CExampleB b;

    QObject::connect(&a,SIGNAL(stateChanged(int)),&b,SLOT(Function(int)));

    a.SetValue(100);

    return 100;

}