[Qt]《开发指南》3.1源码分析

 界面：

 

ButterflyGraph：

可以看出，本工程在主程序main里调用窗口界面qmywidget，窗口界面继承了QWidget，并调用自定义类qperson，推测是qmywidget类中的一个属性

 

qmywidget的实现，调用了显示界面ui_qmywidget，包含了元对象QMetaProperty

 UML图：

QmyWidget中，on开头的都是槽函数，QmyWidget是主窗口，所以不发射信号，只接收信号

main.cpp

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QmyWidget w;
    w.show();

    return a.exec();
}

qperson.h

#ifndef QPERSON_H
#define QPERSON_H

#include <QObject>

class QPerson : public QObject
{
    Q_OBJECT

    Q_CLASSINFO("author","Wang")
    Q_CLASSINFO("company","UPC")
    Q_CLASSINFO("version","1.0.0")

    Q_PROPERTY(int age READ age WRITE setAge NOTIFY ageChanged)
    Q_PROPERTY(QString name MEMBER m_name)
    Q_PROPERTY(int score MEMBER m_score)
private:
    int  m_age=10;
    QString m_name;
    int     m_score=79;
public:
    explicit QPerson(QString fName, QObject *parent = nullptr);

    int     age();
    void    setAge(int value);

    void    incAge();
signals:
    void    ageChanged( int  value);

public slots:
};

#endif // QPERSON_H

qmywidget.cpp

#include "qmywidget.h"
#include "ui_qmywidget.h"
#include    <QMetaProperty>

QmyWidget::QmyWidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::QmyWidget)
{//构造函数
    ui->setupUi(this);

    boy=new QPerson("王小明");
    boy->setProperty("score",95);
    boy->setProperty("age",10);
    boy->setProperty("sex","Boy");//动态属性
//    connect(boy,SIGNAL(ageChanged(int)),this,SLOT(on_ageChanged(int)));
    connect(boy,&QPerson::ageChanged,this,&QmyWidget::on_ageChanged);

    girl=new QPerson("张小丽");
    girl->setProperty("score",81);
    girl->setProperty("age",20);
    girl->setProperty("sex","Girl");//动态属性
    connect(girl,&QPerson::ageChanged,this,&QmyWidget::on_ageChanged);

    ui->spinBoy->setProperty("isBoy",true); //动态属性
    ui->spinGirl->setProperty("isBoy",false);

//  不能使用此形式，因为QSpinBox有两种参数形式的valueChanged()信号
//    connect(ui->spinGirl,&QSpinBox::valueChanged,
//            this,&QmyWidget::on_spinBoy_valueChanged);
    connect(ui->spinGirl,SIGNAL(valueChanged(int)),
            this,SLOT(on_spin_valueChanged(int)));
    connect(ui->spinBoy,SIGNAL(valueChanged(int)),
            this,SLOT(on_spin_valueChanged(int)));
}

QmyWidget::~QmyWidget()
{
    delete ui;
}

void QmyWidget::on_ageChanged( int value)
{//响应QPerson的ageChanged()信号
    Q_UNUSED(value);
    QPerson *aPerson = qobject_cast<QPerson *>(sender()); //类型投射
    QString hisName=aPerson->property("name").toString(); //姓名
//    QString hisName=aPerson->name(); //获取姓名，错误
    QString hisSex=aPerson->property("sex").toString(); //动态属性
    int hisAge=aPerson->age();//通过接口函数获取年龄
//    int hisAge=aPerson->property("age").toInt();//通过属性获得年龄

    ui->textEdit->appendPlainText(hisName+","+hisSex
                               +QString::asprintf(",年龄=%d",hisAge));
}

void QmyWidget::on_btnClear_clicked()
{//"清空文本框"按钮
    ui->textEdit->clear();
}

void QmyWidget::on_btnBoyInc_clicked()
{//"boy长大一岁"按钮
    boy->incAge();
}

void QmyWidget::on_btnGirlInc_clicked()
{//"girl长大一岁"按钮
    girl->incAge();
}

void QmyWidget::on_spin_valueChanged(int arg1)
{//响应界面上spinBox的valueChanged(int)信号
    Q_UNUSED(arg1);
    QSpinBox *spinBox = qobject_cast<QSpinBox *>(sender());
    if (spinBox->property("isBoy").toBool())
        boy->setAge(spinBox->value());
    else
        girl->setAge(spinBox->value());
}

void QmyWidget::on_btnClassInfo_clicked()
{//"类的元对象信息"按钮
    const QMetaObject *meta=boy->metaObject();
//    const QMetaObject *meta=girl->metaObject();
//    const QMetaObject *meta=ui->spinBoy->metaObject();
    ui->textEdit->clear();

    ui->textEdit->appendPlainText("==元对象信息==
");
    ui->textEdit->appendPlainText(QString("类名称：%1
").arg(meta->className()));

    ui->textEdit->appendPlainText("property");
    for (int i=meta->propertyOffset();i<meta->propertyCount();i++)
    {
        const char* propName=meta->property(i).name();
        ui->textEdit->appendPlainText(
           QString("属性名称=%1，属性值=%2").arg(propName).arg(boy->property(propName).toString()));
    }

    ui->textEdit->appendPlainText("");
    ui->textEdit->appendPlainText("classInfo");
    for (int i=meta->classInfoOffset();i<meta->classInfoCount();++i)
    {
       QMetaClassInfo classInfo=meta->classInfo(i);
        ui->textEdit->appendPlainText(
           QString("Name=%1; Value=%2").arg(classInfo.name()).arg(classInfo.value()));
    }

}

qperson.cpp

#include "qperson.h"

QPerson::QPerson(QString fName,QObject *parent) : QObject(parent)
{ //构造函数
    m_name=fName;
}

int QPerson::age()
{ //返回age
    return  m_age;
}

void QPerson::setAge(int value)
{//设置age
    m_age=value;
    emit ageChanged(m_age); //发射信号
}

void QPerson::incAge()
{
    m_age++;
    emit ageChanged(m_age);//发射信号
}