QT5笔记：7. 自定义类、自定义信号及类的元对象信息

• 自定义的QPerson类，需要继承 QObject类

  • qperson.h头文件

    #ifndef QPERSON_H
    #define QPERSON_H
    
    #include <QObject>
    
    class QPerson : public QObject
    {
        Q_OBJECT
        Q_CLASSINFO("author", "……");
        Q_CLASSINFO("company", "……");
        Q_CLASSINFO("version", "1.0");
        Q_PROPERTY(unsigned int age READ age WRITE setAge NOTIFY ageChanged);
        Q_PROPERTY(QString name MEMBER m_name);
        Q_PROPERTY(int score MEMBER m_score);
    
    public:
        explicit QPerson(QString name, QObject *parent = nullptr);
        unsigned int age();
        void setAge(unsigned int val);
        void increaseAge();
    
    private:
        unsigned int m_age = 10;
        QString m_name;
        int m_score = 80;
    
    signals:
        void ageChanged(int age);//自定义的信号
    };
    
    #endif // QPERSON_H
    

  • qperson.cpp 类文件

    #include "qperson.h"
    
    QPerson::QPerson(QString name, QObject *parent) : QObject(parent)
    {
        m_name = name;
    }
    
    unsigned int QPerson::age()
    {
        return m_age;
    }
    
    void QPerson::setAge(unsigned int val)
    {
        if (val != m_age)//当变化时设置值并发射信号
        {
            m_age = val;
            emit(ageChanged(m_age));//发射信号
        }
    }
    
    void QPerson::increaseAge()
    {
        m_age++;
        emit(ageChanged(m_age));//发射信号
    }
    
    

  • widget.h 界面的头文件

  #ifndef WIDGET_H
  #define WIDGET_H
  
  #include <QWidget>
  #include "qperson.h" //自己创建的类，用双引号引入
  
  QT_BEGIN_NAMESPACE
  namespace Ui
  {
      class Widget;
  }
  QT_END_NAMESPACE
  
  class Widget : public QWidget
  {
      Q_OBJECT
  
  public:
      Widget(QWidget *parent = nullptr);
      ~Widget();
  
  private slots: //信号&槽不同于方法，需要写在头文件的这里 private slots
      void on_btnAddBoyAge_clicked();
  
      void on_btnAddGirlAge_clicked();
  
      void on_btnMetaInfo_clicked();
  
      void on_spin_valueChanged(int val);
  
      void on_ageChanged(int age);
  
  private:
      Ui::Widget *ui;
      QPerson *boy;
      QPerson *girl;
  };
  #endif // WIDGET_H
  

  • widget.cpp 界面的类文件

  #include "widget.h"
  #include "ui_widget.h"
  #include <QMetaProperty>
  
  Widget::Widget(QWidget *parent)
      : QWidget(parent), ui(new Ui::Widget)
  {
      ui->setupUi(this);
      ui->spinBoxBoyAge->setProperty("isBoy", true);// 类似于WinForm 的Tag,但是比Tag强大，键值对类型
      ui->spinBoxGirlAge->setProperty("isBoy", false);
  
      boy = new QPerson("张三");
      boy->setAge(12);
      boy->setProperty("score", 99);
      boy->setProperty("sex", "boy"); //动态属性
  //    connect(boy, &QPerson::ageChanged, this, &Widget::on_ageChanged);
      connect(boy, SIGNAL(ageChanged(int)), this, SLOT(on_ageChanged(int)));//链接自定义函数
  
      girl = new QPerson("蕾欧娜");
      girl->setAge(15);
      girl->setProperty("score", 120);
      girl->setProperty("sex", "girl"); //动态属性
      connect(girl, SIGNAL(ageChanged(int)), this, SLOT(on_ageChanged(int)));
  
      connect(ui->spinBoxBoyAge, SIGNAL(valueChanged(int)), this, SLOT(on_spin_valueChanged(int)));
      connect(ui->spinBoxGirlAge, SIGNAL(valueChanged(int)), this, SLOT(on_spin_valueChanged(int)));
  }
  
  Widget::~Widget()
  {
      delete ui;
  }
  
  void Widget::on_btnAddBoyAge_clicked()
  {
      boy->increaseAge();
  }
  
  void Widget::on_btnAddGirlAge_clicked()
  {
      girl->increaseAge();
  }
  
  /**
   * @brief Widget::on_btnMetaInfo_clicked 元对象信息：对象信息和类的信息
   */
  void Widget::on_btnMetaInfo_clicked()
  {
      ui->textBoxInfo->clear();
      const QMetaObject *metaGirl = girl->metaObject();
      ui->textBoxInfo->appendPlainText("【对象信息】");
      ui->textBoxInfo->appendPlainText(QString("类名称：%1").arg(metaGirl->className()));
      QString text = QString::Null();
      for (int i = metaGirl->propertyOffset(); i < metaGirl->propertyCount(); i++)//属性的获取方式
      {
          QMetaProperty property = metaGirl->property(i);
          const char *name = property.name();
          QString value = girl->property(name).toString();
          text += QString("属性名：%1").arg(name) + "\t值：" + value + "\n";//字符串的拼接
      }
      ui->textBoxInfo->appendPlainText(text);
      ui->textBoxInfo->appendPlainText("【类信息】");
      QString classInfo = QString::Null();
      for (int i = metaGirl->classInfoOffset(); i < metaGirl->classInfoCount(); i++)
      {
          QMetaClassInfo classInf = metaGirl->classInfo(i);
          const char *name = classInf.name();
          const char *value = classInf.value();
          classInfo += QString("属性名：%1\t值：%2\n").arg(name).arg(value);//格式化字符串拼接函数
      }
      ui->textBoxInfo->appendPlainText(classInfo);
  }
  
  void Widget::on_spin_valueChanged(int val)
  {
      Q_UNUSED(val);//标明这个变量unused
      QSpinBox *box = qobject_cast<QSpinBox *>(sender());//类似于WinForm 的事件里的sender，一样需要类型转换，并且类型不匹配时返回null
      if (box->property("isBoy").toBool())
          boy->setAge(box->value());
      else
          girl->setAge(box->value());
  }
  
  void Widget::on_ageChanged(int age)
  {
      Q_UNUSED(age);//标明这个变量unused
      QPerson *person = qobject_cast<QPerson *>(sender());
      QString name = person->property("name").toString();
      QString sex = person->property("sex").toString();
      unsigned int p_age = person->age();
      ui->textBoxInfo->appendPlainText("姓名：" + name + " ,性别：" + sex + ", 年龄：" + QString::asprintf("%d", p_age));//格式化输出
  
      if (person->property("sex").toString() == "boy")
          ui->spinBoxBoyAge->setValue(p_age);
      else
          ui->spinBoxGirlAge->setValue(p_age);
  }
  
  

  • 最终界面样式