定义可以导出的C++类

colormaker.h文件

#ifndef COLORMAKER_H
#define COLORMAKER_H
#include <QObject>
#include <QColor>

class ColorMaker: public QObject
{
    Q_OBJECT
    Q_ENUMS(GenerateAlgorithm)     //枚举类型
    Q_PROPERTY(QColor color READ getColor WRITE setColor NOTIFY colorChanged)    //属性，color是对象，
    Q_PROPERTY(QColor timeColor READ timeColor)

public:
    ColorMaker(QObject *parent = 0);
    ~ColorMaker();

    enum GenerateAlgorithm{      //枚举类型
        RandomRGB,
        RandomRed,
        RandomGreen,
        RandomBlue,
        LinearIncrease
    };

    QColor getColor() const;
    void setColor(const QColor & color);
    QColor timeColor() const;

    /*Q_PROPERTY(                //通过他定义的属性，可以在QML中访问，修改。
            (READ getFunction [WIRTE setFunction] |
             MEMBER memberName [(READ getFunction | WRITE setFunction)])
            [RESET resetFunction]
            [NOTIFY notifySignal]
            [REVISION int]
            [DESIGNABLE bool]
            [SCRIPTABLE bool]
            [STORED bool]
            [USER bool]
            [CONSTANT]
            [FINAL]
            )
    */
    Q_INVOKABLE GenerateAlgorithm algorithm() const;                 //修饰类的成员函数
    Q_INVOKABLE void setAlgorithm (GenerateAlgorithm algorithm);     //修饰类的成员函数

signals:
    void colorChanged(const QColor & color);     //信号
    void currentTime(const QString &strTime);    //信号

public slots:
    void start();      //槽
    void stop();       //槽

protected:
    void timerEvent (QTimerEvent *e);

private:
    GenerateAlgorithm m_algorithm;
    QColor m_currentColor;
    int m_nColorTimer;
};

#endif // COLORMAKER_H

colormaker.cpp文件

#include "colormaker.h"
#include <QTimerEvent>
#include <QDateTime>

ColorMaker::ColorMaker(QObject *parent)

    :QObject(parent)
    ,m_algorithm(RandomRGB)
    ,m_currentColor(Qt::black)
    ,m_nColorTimer(0)


{
    qsrand(QDateTime::currentDateTime() .toTime_t());
}

ColorMaker::~ColorMaker()
{

}

QColor ColorMaker::getColor() const
{
    return m_currentColor;
}

void ColorMaker::setColor(const QColor &color)
{
    m_currentColor = color;
    emit colorChanged(m_currentColor);
}

QColor ColorMaker::timeColor() const
{
    QTime time = QTime::currentTime();
    int r = time.hour();
    int g = time.minute()*2;
    int b = time.second()*4;
    return QColor::fromRgb(r,g,b);
}

ColorMaker::GenerateAlgorithm ColorMaker::algorithm() const
{
    return m_algorithm;
}

void ColorMaker::setAlgorithm(GenerateAlgorithm algorithm)
{
    m_algorithm = algorithm;
}

void ColorMaker::start()
{
    if(m_nColorTimer == 0);
    {
        m_nColorTimer = startTimer(1000);
    }
}

void ColorMaker::stop()
{
    if(m_nColorTimer > 0)
    {
        killTimer(m_nColorTimer);
        m_nColorTimer = 0;
    }
}

void ColorMaker::timerEvent(QTimerEvent *e)
{
    if(e->timerId() == m_nColorTimer)
    {
        switch(m_algorithm)
        {
        case RandomRGB:
            m_currentColor.setRgb(qrand() % 255, qrand() % 255,qrand() % 255);
            break;
        case RandomRed:
            m_currentColor.setRed(qrand() % 255);
            break;
        case RandomGreen:
            m_currentColor.setGreen(qrand() % 255);
            break;
        case RandomBlue:
            m_currentColor.setBlue(qrand() % 255);
            break;
        case LinearIncrease:
            {
                int r = m_currentColor.red() + 10;
                int g = m_currentColor.green() +10;
                int b = m_currentColor.blue() + 10;
                m_currentColor.setRgb(r % 255,g % 255,b % 255);
            }
            break;
        }
        emit colorChanged(m_currentColor);
        emit currentTime(QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss"));
    }
    else
    {
        QObject::timerEvent(e);
    }
}

main.cpp文件

#include <QGuiApplication>
#include <QtQuick>
#include <QtQml>
//#include <QQmlApplicationEngine>
#include <colormaker.h>

int main(int argc, char *argv[])
{
    //QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);
    qmlRegisterType<ColorMaker>("an.qt.ColorMaker",1,0,"ColorMaker");


    //QQmlApplicationEngine engine;
   //engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    //if (engine.rootObjects().isEmpty())
       // return -1;
    QQuickView viewer;
    viewer.setResizeMode(QQuickView::SizeRootObjectToView);
    viewer.setSource(QUrl("qrc://main.qml"));
    viewer.show();

    return app.exec();
}

main.qml文件

import QtQuick 2.9
import QtQuick.Controls 1.0
import an.qt.ColorMaker 1.0

Rectangle{
        width: 360;
        height: 360;
        Text {
            id: timeLabel;
            anchors.left: parent.left;
            anchors.leftMargin: 4;
            anchors.top: parent.top;
            anchors.topMargin: 4;
            font.pixelSize: 26;
        }
        ColorMaker{
            id:colormaker;
            color: Qt.green;
        }
        Rectangle{
            id:colorRect;
            anchors.centerIn: parent;
            width: 200;
            height: 200;
            color: "blue";
        }
        Button{
            id:start;
            text: "start";
            anchors.left: parent.left;
            anchors.leftMargin: 4;
            anchors.bottom: parent.bottom;
            anchors.bottomMargin: 4;
            onClicked: {
                colormaker.start();
            }
        }
        Button{
            id:stop;
            text: "stop";
            anchors.left: start.right;
            anchors.leftMargin: 4;
            anchors.bottom: start.bottom;
            onClicked: {
                colormaker.stop();
            }
        }
        function changeAlgorithm(button,algorithm){
            switch(algorithm){
            case 0;
                button.text = "RandomRGB";
                break;
            case 1;
                button.text = "RandomRed";
                break;
            case 2
                button.text = "RandomGreen";
                break;
            case 3;
                button.text = "RandomBlue";
                break;
            case 4;
                button.text = "LinearIncrease";
                break;
            }
        }
        Button{
            id:colorAlgorithm;
            text:"RandomRGB";
            anchors.left: stop.right;
            anchors.leftMargin: 4;
            anchors.bottom: start.bottom;
            onClicked: {
                var algorithm = (colormaker.algorithm() + 1) % 5;
                    changeAlgorithm(ColorAnimation,algorithm);
                    colormaker.setAlgorithm(algorithm);
                }
        }
        Button{
                id:quit;
                text:"quit";
                anchors.left: colorAlgorithm.right;
                anchors.leftMargin: 4;
                anchors.bottom: start.bottom;
                onClicked:{Qt.quit();}
        }
        Component.objectName: {
            colormaker.color = Qt.rgba(0,180,120,255);
            colormaker.setAlgorithm(ColorMaker.LinearIncrease);
            changeAlgorithm(ColorAlgorithm,colormaker.algorithm());
        }
        Connections{
            target:colormaker;
            onCurrentTime:{
                timeLabel.text = strTime;
                timeLabel.color = colormaker.timeColor;
            }
        }
        Connections{
            target:colormaker;
            onColorChanged: {
                colorRect.color = color;
            }
        }
}