Qt（五）元对象特性

一、UI设计

新建项目，主要选项如下图：一个QWidget，带ui文件，并初步Ui设计
拖动组件：QLable,QPushButton,QSpinBox,QPlainTextEdit。

详情ui文件

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Widget</class>
 <widget class="QWidget" name="Widget">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>534</width>
    <height>388</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Widget</string>
  </property>
  <layout class="QGridLayout" name="gridLayout_2">
   <item row="0" column="0">
    <layout class="QGridLayout" name="gridLayout">
     <item row="0" column="0">
      <widget class="QLabel" name="label">
       <property name="text">
        <string>设置男孩年龄</string>
       </property>
      </widget>
     </item>
     <item row="0" column="1">
      <widget class="QSpinBox" name="spinBoxBoy">
       <property name="value">
        <number>10</number>
       </property>
      </widget>
     </item>
     <item row="0" column="2">
      <widget class="QPushButton" name="pushButtonBoyUp">
       <property name="text">
        <string>boy_up_age</string>
       </property>
      </widget>
     </item>
     <item row="0" column="3">
      <widget class="QPushButton" name="pushButtonMetaInfo">
       <property name="text">
        <string>类的元对象信息</string>
       </property>
      </widget>
     </item>
     <item row="1" column="0">
      <widget class="QLabel" name="label_2">
       <property name="text">
        <string>设置女孩年龄</string>
       </property>
      </widget>
     </item>
     <item row="1" column="1">
      <widget class="QSpinBox" name="spinBoxGirl">
       <property name="value">
        <number>5</number>
       </property>
      </widget>
     </item>
     <item row="1" column="2">
      <widget class="QPushButton" name="pushButtonGirlUp">
       <property name="text">
        <string>girl_up_age</string>
       </property>
      </widget>
     </item>
     <item row="1" column="3">
      <widget class="QPushButton" name="pushButtonClear">
       <property name="text">
        <string>清空对话框</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
   <item row="1" column="0">
    <widget class="QPlainTextEdit" name="txtEdit"/>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections>
  <connection>
   <sender>pushButtonClear</sender>
   <signal>clicked()</signal>
   <receiver>txtEdit</receiver>
   <slot>clear()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>461</x>
     <y>57</y>
    </hint>
    <hint type="destinationlabel">
     <x>266</x>
     <y>228</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

二、代码开发

新建类QPerson

qperson.h

#ifndef QPERSON_H
#define QPERSON_H

#include <QObject>

class QPerson : public QObject
{
    
    
    Q_OBJECT
    Q_CLASSINFO("author","wsp_1138886114")
    Q_CLASSINFO("company","SH")
    Q_CLASSINFO("version","1.0")

    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 = 10;
    QString m_name;
    int m_score = 79;

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

signals:
    void ageChanged(unsigned value);
};

#endif // QPERSON_H

qperson.cpp

#include "qperson.h"

QPerson::QPerson(QString name, QObject *parent) : QObject(parent)
{
    
    
    m_name = name;
}

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

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

void QPerson::ageInc()
{
    
    
    m_age++;
    emit(ageChanged(m_age));
}

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include "qperson.h"

QT_BEGIN_NAMESPACE
namespace Ui {
    
     class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    
    
    Q_OBJECT
private:
    QPerson* boy;
    QPerson* girl;

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

private:
    Ui::Widget *ui;
    void on_ageChanged(unsigned value);


private slots:
    void on_pushButtonBoyUp_clicked();
    void on_pushButtonGirlUp_clicked();
    void on_pushButtonMetaInfo_clicked();
    void on_spin_valueChanged(int arg1);
};
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QMetaProperty>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    
    
    ui->setupUi(this);
    ui->spinBoxBoy->setProperty("isBoy",true);
    ui->spinBoxGirl->setProperty("isBoy",false);

    boy = new QPerson("小明");
    boy->setProperty("score",95);
    boy->setProperty("age",10);
    boy->setProperty("sex","Boy");
    connect(boy,&QPerson::ageChanged,this,&Widget::on_ageChanged);

    girl = new QPerson("小花");
    girl->setProperty("score",99);
    girl->setProperty("age",9);
    girl->setProperty("sex","girl");
    connect(girl,&QPerson::ageChanged,this,&Widget::on_ageChanged);

    connect(ui->spinBoxBoy,SIGNAL(valueChanged(int)),this,SLOT(on_spin_valueChanged(int)));
    connect(ui->spinBoxGirl,SIGNAL(valueChanged(int)),this,SLOT(on_spin_valueChanged(int)));
}

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

void Widget::on_ageChanged(unsigned value)
{
    
    
    Q_UNUSED(value)
    QPerson* aPerson = qobject_cast<QPerson*>(sender());
    QString aName = aPerson->property("name").toString();
    QString aSex = aPerson->property("sex").toString();
    unsigned aAge = aPerson->age();
    ui->txtEdit->appendPlainText(aName+","+aSex+QString::asprintf(" 年龄=%d",aAge));
}

void Widget::on_spin_valueChanged(int arg1)
{
    
    
    Q_UNUSED(arg1)
    QSpinBox* spinBox = qobject_cast<QSpinBox*>(sender());
    if (spinBox->property("isBoy").toBool())
        boy->setAge(spinBox->value());
    else
        girl->setAge(spinBox->value());
}

void Widget::on_pushButtonBoyUp_clicked()
{
    
    
    boy->ageInc();
}

void Widget::on_pushButtonGirlUp_clicked()
{
    
    
    girl->ageInc();
}

void Widget::on_pushButtonMetaInfo_clicked()
{
    
    
    const QMetaObject* meta = girl->metaObject();
    ui->txtEdit->clear();
    ui->txtEdit->appendPlainText("===元对象信息====\n");
    ui->txtEdit->appendPlainText(
                QString("类名称：%1\n").arg(meta->className()));
    ui->txtEdit->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->txtEdit->appendPlainText(
                    QString("属性名称：%1、属性值 %2").arg(propName).arg(propValue));

    }
    ui->txtEdit->appendPlainText("");
    ui->txtEdit->appendPlainText("classInfo");

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

main.cpp

#include "widget.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    
    
    QApplication a(argc, argv);
    Widget w;
    w.show();
    return a.exec();
}

三、演示