QML与C++交互

短命女 2022-12-26 08:19 125阅读 0赞

** cplusplusexchange.h：**

#ifndef CPLUSPLUSEXCHANGE_H
    #define CPLUSPLUSEXCHANGE_H
    
    #include <QObject>
    
    class CPlusPlusExchange : public QObject
    {
    
        Q_OBJECT
        Q_PROPERTY(QString name READ getName WRITE setName)
    public:
        CPlusPlusExchange(QObject * object = nullptr);
    
        //给类属性添加访问方法
        QString getName();
    
        //给类属性添加访问方法
        void setName(QString);
    
        //通过Q_INVOKABLE宏标记的public函数可以在QML中访问
        Q_INVOKABLE void print(QString text);
    
        Q_INVOKABLE void sendSignal();
    signals:
        //信号可以在QML中访问
        void signalA();//一个无参信号
        void signalB(const QString &str,int value);//一个带参数信号
        void nameChanged(const QString name);
    
    public slots:
        //public槽函数可以在QML中访问
        void slotA();//一个无参槽函数
        void slotB(const QString &str,int value);//一个带参数槽函数
    
    private:
        QString name;
    };
    
    #endif // CPLUSPLUSEXCHANGE_H

**cplusplusexchange.cpp：**

#include "cplusplusexchange.h"
    #include <QDebug>
    CPlusPlusExchange::CPlusPlusExchange(QObject * object) : QObject(object)
    {
    
    }
    
    
    //给类属性添加访问方法
    QString CPlusPlusExchange::getName(){
        qDebug() << "QString CPlusPlusExchange::getName()";
        return name;
    }
    
    //给类属性添加访问方法
    void CPlusPlusExchange::setName(QString name){
        this->name = name;
        qDebug() << "void CPlusPlusExchange::setName(QString name)";
    }
    
    
    //通过Q_INVOKABLE宏标记的public函数可以在QML中访问
    void CPlusPlusExchange::print(QString text){
        qDebug() << "void CPlusPlusExchange::print(QString text)";
        qDebug() << text;
    }
    
    
    //public槽函数可以在QML中访问
    void CPlusPlusExchange::slotA(){
        qDebug() << "void CPlusPlusExchange::slotA()";
    }
    
    
    void CPlusPlusExchange::slotB(const QString &str,int value){
        qDebug() << "void CPlusPlusExchange::slotB(const QString &str,int value)";
    
        qDebug() << str + ";" + value;
    }
    
    
    void CPlusPlusExchange::sendSignal(){
        emit signalA();
    }

**main.cpp： **

#include <QGuiApplication>
    #include <QQmlApplicationEngine>
    #include <QQmlContext>
    #include "cplusplusexchange.h"
    int main(int argc, char *argv[])
    {
        QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    
        QGuiApplication app(argc, argv);
    
        QQmlApplicationEngine engine;
    
        //设置rootContext的变量
        QQmlContext * context = engine.rootContext();
    
        CPlusPlusExchange * plusPlusExchange = new CPlusPlusExchange(nullptr);
        context->setContextProperty("plusPlusExchange",plusPlusExchange);
    
        const QUrl url(QStringLiteral("qrc:/main.qml"));
        QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                         &app, [url](QObject *obj, const QUrl &objUrl) {
            if (!obj && url == objUrl)
                QCoreApplication::exit(-1);
        }, Qt::QueuedConnection);
        engine.load(url);
    
        return app.exec();
    }

**main.qml：**

import QtQuick 2.14
    import QtQuick.Window 2.14
    import QtQuick.Controls 2.14
    import QtQml.Models 2.14
    import QtQuick.Dialogs 1.2
    Window {
        id: window
        visible: true
        width: 640
        height: 480
        title: qsTr("Hello World")
    
    
        Component.onCompleted: {
    
            //会调用void setName(QString);
            plusPlusExchange.name = "王天龙";
    
            //会调用QString getName();
            console.log(plusPlusExchange.name);
    
            plusPlusExchange.print("test");
    
    
            plusPlusExchange.signalA.connect(()=>{
                                                 console.log("信号被捕捉");
                                             });
    
    
            plusPlusExchange.sendSignal();
    
        }
    }

**执行结果：**

![20201203203707563.png][]

[20201203203707563.png]: /images/20221120/3e4a205cbd1348f9ba0bc50d4735cd36.png