qml 与 c++交互

àì夳堔傛蜴生んèń 2022-07-16 08:57 170阅读 0赞

感觉qml，有利有弊，编写业务逻辑，使用起来感觉不爽。

qml界面语言与qt c++交互麻烦。c++到qml都要qmlRegisterType方式，  setContextProperty 方式。

qml到c++，就像解析xml一样，找啊找啊

1，qml调用c++  qmlRegisterType方式

#include "mainwindow.h"
    #include <QApplication>
    #include <QScrollArea>
    #include <QPushButton>
    #include <QLabel>
    #include <QImage>
    #include <QQmlEngine>
    #include <QtQml>
    #include <QGuiApplication>
    #include <QQmlApplicationEngine>
    #include <QQuickItem>
    #include <QMetaObject>
    #include <QDebug>
    #include <QColor>
    #include <QVariant>
    
    
    int main(int argc, char *argv[])
    {
        QGuiApplication app(argc, argv);
        qmlRegisterType<ColorMaker>("an.qt.ColorMaker", 1, 0, "ColorMaker");
        QQmlApplicationEngine engine;
        //engine.rootContext()->setContextProperty("colorMaker", new ColorMaker);
        engine.load(QUrl(QStringLiteral("qrc:/cpptoQml.qml")));
        return app.exec();
    }

class ColorMaker : public QObject
    {
        Q_OBJECT
    
    public:
    
        int nn = 0;
        Q_INVOKABLE  int setA(int a)
        {
            nn = a;
            return nn;
        }
    
    signals:
        void colorChanged(const QColor & color);
    
        void currentTime(const QString &strTime);
    
    public slots:
        void start()
        {
            qDebug() << "qqqq" << nn;
        }
    
        void stop()
        {
    
        }
    };

import QtQuick 2.4
    import QtQuick.Window 2.2
    import QtQuick.Controls 1.2
    import QtQuick.Controls.Styles 1.4
    import an.qt.ColorMaker 1.0
    Window {
        id:rootid
        objectName: "rootid";
        visible: true
        width: 640
        height: 480
        title: qsTr("Hello World qt5")
        color: "gray"
        Item {
            ColorMaker {
            id:colorMaker;
    
            }
            width: 200
            height: 200
            visible: true
            layer.enabled: true
            id: nonLayered
            focus: true
            Keys.enabled: true
            Keys.onPressed:  {
                var component;
                var sprite;
                if(focus == true)
                {
                    console.log("mouse button onSpacePressed 1")
    
                    var n = colorMaker.setA(100);
                    console.log("mouse button onSpacePressed " + n );
                    colorMaker.start();
                }
                else
                    console.log("mouse button onSpacePressed")
            }
        }
        Text {
            objectName: "textID";
            id:textID
            x:100
            y:100
            font { pixelSize: 19; bold: true }
            text: "dddddddddddddddd"
    
        }
    }

2，qml调用c++  setContextProperty

修改这里

import QtQuick 2.4
    import QtQuick.Window 2.2
    import QtQuick.Controls 1.2
    import QtQuick.Controls.Styles 1.4
    //import an.qt.ColorMaker 1.0
    Window {
        id:rootid
        objectName: "rootid";
        visible: true
        width: 640
        height: 480
        title: qsTr("Hello World qt5")
        color: "gray"
        Item {
            /*ColorMaker {
            id:colorMaker;
    
            }*/
            width: 200
            height: 200
            visible: true

3，c++调用qml

int main(int argc, char *argv[])
    {
        QGuiApplication app(argc, argv);
        //qmlRegisterType<ColorMaker>("an.qt.ColorMaker", 1, 0, "ColorMaker");
        QQmlApplicationEngine engine;
        engine.rootContext()->setContextProperty("colorMaker", new ColorMaker);
        engine.load(QUrl(QStringLiteral("qrc:/cpptoQml.qml")));
    
    
    
        QObject * rootItem  = 0;
        QList<QObject*> listQ = engine.rootObjects();
        for(  QList<QObject*>::iterator it = listQ.begin();it != listQ.end();++it)
        {
            qDebug() << " return - " << (*it)->objectName();
            if( (*it)->objectName() == "rootid")
            {
                rootItem = *it;
                break;
            }
    
        }
        if(!rootItem)
            return 0;
        QObject * textLabel = rootItem->findChild<QObject*>("textID");
        if(textLabel)
        {
            bool bRet = QMetaObject::invokeMethod(textLabel, "setText", Q_ARG(QString, "world hello"));
            qDebug() << "call setText return - " << bRet;
            textLabel->setProperty("color", QColor::fromRgb(255,0,0));
            textLabel->setProperty("text",  QString("world hello"));
            bRet = QMetaObject::invokeMethod(textLabel, "doLayout");
            qDebug() << "call doLayout return - " << bRet;
    
        }
        return app.exec();
    }