元对象特性测试实例

1目标

2步骤

1）创建类Person，成员变量，构造函数，自定义信号

2）实现person的一些函数

3）在widget中添加person类型的成员变量

4）初始化，连接信号和槽

5）槽函数1

6）槽函数2 自定义的槽函数，需要通过connect连接信号ageChanged和槽函数on_ageChanged

7）槽函数3 输出元对象信息，包括属性键值对和QClassInfo键值对

3细节代码

源代码链接：https://download.csdn.net/download/weixin_44500344/86543158
1）qperson.h文件

#ifndef QPERSON_H
#define QPERSON_H

#include 

class QPerson : public QObject
{
    Q_OBJECT
    Q_CLASSINFO("author","cuiqianqian")
    Q_CLASSINFO("company","university")
    Q_PROPERTY(unsigned age READ age WRITE setAge NOTIFY ageChanged)
    Q_PROPERTY(QString name MEMBER m_name)
    Q_PROPERTY(int score MEMBER m_score)

private:
    unsigned m_age;
    QString m_name;
    int m_score;

public:
    explicit QPerson(QString name,unsigned age,int score,QObject *parent = nullptr);
    unsigned age();
    void setAge(unsigned value);
    void incAge();

signals:
    void ageChanged(unsigned value);

public slots:

};

#endif // QPERSON_H

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2）qperson.cpp文件

#include "qperson.h"

QPerson::QPerson(QString name,unsigned age,int score,QObject *parent) : QObject(parent)
{
    m_name=name;
    m_age=age;
    m_score=score;
}

unsigned QPerson::age()
{
    return m_age;
}

void QPerson::setAge(unsigned value)
{
    m_age=value;
    emit(ageChanged(m_age));
}


void QPerson::incAge()
{
    m_age++;
}

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3）widget.h文件

#ifndef WIDGET_H
#define WIDGET_H

#include 
#include 
#include 
#include 
#include "qperson.h"
namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();

private slots:
    void on_clearButton_clicked();

    void on_boyButton_clicked();

    void on_girlButton_clicked();

    void on_boyBox_valueChanged(int arg1);

    void on_girlBox_valueChanged(int arg1);

    void on_classInfoButton_clicked();

    //自定义槽函数
    void on_ageChanged();

private:
    Ui::Widget *ui;
    QPerson *boy;
    QPerson *girl;
};

#endif // WIDGET_H

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4）widget.cpp文件

#include "widget.h"
#include "ui_widget.h"
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    //初始化
    boy = new QPerson("张三",11,90);
    girl= new QPerson("小红",21,100);
    ui->boyBox->setValue(boy->age());
    ui->girlBox->setValue(girl->age());

    //当调用person->setAge()，会发出ageChanged函数，执行on_ageChanged()槽函数，输出成员信息
    connect(boy,&QPerson::ageChanged,this,&Widget::on_ageChanged);
    connect(girl,&QPerson::ageChanged,this,&Widget::on_ageChanged);
}

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

void Widget::on_clearButton_clicked()
{
    ui->plainTextEdit->clear();
}
//男孩长一岁
void Widget::on_boyButton_clicked()
{
    boy->incAge();
    ui->boyBox->setValue(boy->age());
}
//女孩长一岁
void Widget::on_girlButton_clicked()
{
    girl->incAge();
    ui->girlBox->setValue(girl->age());
}

void Widget::on_boyBox_valueChanged(int arg1)
{
    boy->setAge(arg1);
}
void Widget::on_girlBox_valueChanged(int arg1)
{
    girl->setAge(arg1);
}

//自定义的槽函数
void Widget::on_ageChanged()
{
    //显示成员信息
    QPerson *aPerson=qobject_cast<QPerson *>(sender());
    QString aName=aPerson->property("name").toString();
    unsigned aAge=aPerson->age();
    int aSorce=aPerson->property("score").toInt();
    ui->plainTextEdit->appendPlainText(aName+
                                       QString::asprintf(",年龄=%d,成绩=%d",aAge,aSorce));
}

void Widget::on_classInfoButton_clicked()
{
    const QMetaObject *meta=boy->metaObject();
    ui->plainTextEdit->clear();
    ui->plainTextEdit->appendPlainText("==元对象信息==");
    ui->plainTextEdit->appendPlainText(
                QString("类命名：%1\n").arg(meta->className()));
    ui->plainTextEdit->appendPlainText("property");
    for(int i=meta->propertyOffset();i<meta->propertyCount();i++){
        QMetaProperty prop=meta->property(i);
        const char *propName=prop.name();
        QString propValue=boy->property(propName).toString();
        ui->plainTextEdit->appendPlainText(
                    QString("属性名称：%1，属性值：%2").arg(propName).arg(propValue));
    }

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

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