在QML中使用QSystemTrayIcon(系统托盘)

末蓝、 2022-05-28 11:08 350阅读 0赞

### **【写在前面】** ###

写这篇文章的时候应该不算晚，因为 qml 中并没有正式的系统托盘组件。

但是，在 Qt Labs Platform 模块中( 实验模块，Qt 5.8引入 )，已经有了 SystemTrayIcon，相信以后会作为正式的模块进入 qml。

即便如此，本文仍提供了一种在qml中使用 QSystemTrayIcon 的方法，或者也可以作为 qml 与 c++ 交互的例子来看。

--------------------

### **【正文开始】** ###

先上完成后的 qml 代码：

main.qml

import QtQuick 2.7
    import QtQuick.Window 2.2
    import an.utility 1.0
    
    Window
    {
        id: root
        visible: true
        width: 400
        height: 200
        title: qsTr("Hello World")
    
        Rectangle
        {
            anchors.fill: parent
            color: "red"
        }
    
        SystemTray
        {
            id: systemTray
            menu: menu
            visible: true
            icon: "qrc:/winIcon.png"
            toolTip: "托盘运行中..."
            onTrigger:
            {
                root.requestActivate();
                root.show();
            }
    
            MyMenu
            {
                id: menu
    
                MyAction
                {
                    text: "我在线上"
                    icon: "qrc:/winIcon.png"
                }
    
                MyAction
                {
                    text: "Q我吧"
                    icon: "qrc:/winIcon.png"
                }
    
                MySeparator {}
    
                MyAction
                {
                    text: "离开"
                    icon: "qrc:/winIcon.png"
                }
    
                MyAction
                {
                    text: "忙碌"
                    icon: "qrc:/winIcon.png"
                }
            }
        }
    }

效果图：

![20180404100650676][]

可以看到，效果和 widget 下使用是一样的，但用 qml 更简单更方便。

自定义的 SystemTrayIcon 我注册到 an.utility 1.0 中。下面讲解其实现。

systemtrayicon.h

#ifndef SYSTEMTRAYICON_H
    #define SYSTEMTRAYICON_H
    
    #include <QAction>
    #include <QQuickItem>
    #include <QSystemTrayIcon>
    
    class MyAction : public QAction
    {
        Q_OBJECT
        Q_PROPERTY(QUrl icon READ icon WRITE setIcon NOTIFY iconChanged)    //Q_PROPERTY宏提供在qml中访问的信号槽等等
    
    public:
        MyAction(QObject *parent = nullptr);
        ~MyAction();
    
        QUrl icon() const;
    
    signals:
        void iconChanged();
    
    public slots:
        void setIcon(const QUrl &arg);
    
    private:
        QUrl m_icon;
    };
    
    
    class MySeparator : public QObject
    {
    public:
        MySeparator(QObject *parent = nullptr);
        ~MySeparator();
    };
    
    class SystemTray;
    class MyMenu : public QQuickItem
    {
        Q_OBJECT
        Q_PROPERTY(int width READ width WRITE setWidth NOTIFY widthChanged)
        Q_PROPERTY(int height READ height WRITE setHeight NOTIFY heightChanged)
    
    public:
        MyMenu(QQuickItem *parent = nullptr);
        ~MyMenu();
    
        int width() const;
        int height() const;
        void clear();
    
    signals:
        void widthChanged();
        void heightChanged();
    
    public slots:
        void setWidth(int arg);
        void setHeight(int arg);
        void addSeparator();
        void addAction(MyAction *action);
        void addMenu(MyMenu *menu);
    
    protected:
        void componentComplete();
    
    private:
        friend class SystemTrayIcon;    //让SystemTray能够直接访问m_menu
        QMenu *m_menu;
    };
    
    class SystemTrayIcon : public QQuickItem
    {
        Q_OBJECT
        Q_PROPERTY(int x READ x CONSTANT)
        Q_PROPERTY(int y READ y CONSTANT)
        Q_PROPERTY(QUrl icon READ icon WRITE setIcon NOTIFY iconChanged)
        Q_PROPERTY(QString toolTip READ toolTip WRITE setToolTip NOTIFY toolTipChanged)
        Q_PROPERTY(MyMenu* menu READ menu WRITE setMenu NOTIFY menuChanged)
    
    public:
        SystemTrayIcon(QQuickItem *parent = nullptr);
        ~SystemTrayIcon();
    
        int x() const;
        int y() const;
        QUrl icon() const;
        QString toolTip() const;
        MyMenu* menu() const;
    
    signals:
        void trigger();
        void iconChanged();
        void toolTipChanged();
        void menuChanged();
    
    public slots:
        void setIcon(const QUrl &arg);
        void setToolTip(const QString &arg);
        void setMenu(MyMenu *arg);
        void onVisibleChanged();
        void onActivated(QSystemTrayIcon::ActivationReason reason);
        void onExit();
    
    private:
        QSystemTrayIcon *m_systemTray;
        MyMenu *m_menu;
        QString m_toolTip;
        QUrl m_icon;
    };
    
    #endif // SYSTEMTRAYICON_H

要将 c++ 类导入到 qml 必须继承自 QObject 或其派生类，并使用 Q\_OBJECT 宏。

而继承 QQuickItem 是为了得到 item 中的其他一些属性和信号，以及重实现 *void componentComplete()。*

该函数在组件完成时调用，重新实现来添加必要的操作。

systemTrayIcon.cpp

#include <QApplication>
    #include <QMenu>
    #include <QAction>
    #include "systemtrayicon.h"
    
    MyAction::MyAction(QObject *parent)
        :   QAction(parent)
    {
        setObjectName("MyAction");
    }
    
    MyAction::~MyAction()
    {
    
    }
    
    QUrl MyAction::icon() const
    {
        return m_icon;
    }
    
    void MyAction::setIcon(const QUrl &arg)
    {
        if(m_icon != arg)
        {
            QString str = arg.toLocalFile();
            if(str == "") str = arg.toString();     //如果转换失败
            if( str.mid (0, 3) == "qrc")
                str = str.mid (3, str.count() - 3);
            QAction::setIcon(QIcon(str));
            m_icon = arg;
            emit iconChanged();
        }
    }
    
    MySeparator::MySeparator(QObject *parent)
        :   QObject(parent)
    {
        setObjectName("MySeparator");
    }
    
    MySeparator::~MySeparator()
    {
    
    }
    
    MyMenu::MyMenu(QQuickItem *parent)
        :   QQuickItem(parent)
    {
        setObjectName("MyMenu");
        m_menu = new QMenu();
    }
    
    MyMenu::~MyMenu()
    {
    
    }
    
    int MyMenu::width() const
    {
        return m_menu->width();
    }
    
    int MyMenu::height() const
    {
        return m_menu->height();
    }
    
    void MyMenu::clear()    //清空caidan
    {
        m_menu->clear();
    }
    
    void MyMenu::setWidth(int arg)
    {
        if (m_menu->width() != arg)
        {
            m_menu->setFixedWidth(arg);
            emit widthChanged();
        }
    }
    
    void MyMenu::setHeight(int arg)
    {
        if (m_menu->height() != arg)
        {
            m_menu->setFixedHeight(arg);
            emit heightChanged();
        }
    }
    
    void MyMenu::addAction(MyAction *action)
    {
        m_menu->addAction(action);
    }
    
    void MyMenu::addSeparator()
    {
        m_menu->addSeparator();
    }
    
    void MyMenu::addMenu(MyMenu *menu)
    {
        m_menu->addMenu(menu->m_menu);
    }
    
    void MyMenu::componentComplete()        //在菜单完成构建后调用，将自定义Action,Menu,Separator通过objectName判断加入
    {
        QQuickItem::componentComplete();
        QObjectList list = children();
        for (auto it : list)
        {
            if (it->objectName() == "MyAction")
            {
                MyAction *action = qobject_cast<MyAction *>(it);
                m_menu->addAction(action);
            }
            else if (it->objectName() == "MySeparator")
            {
                m_menu->addSeparator();
            }
            else if (it->objectName() == "MyMenu")
            {
                MyMenu *menu = qobject_cast<MyMenu *>(it);
                m_menu->addMenu(menu->m_menu);
            }
        }
    }
    
    SystemTrayIcon::SystemTrayIcon(QQuickItem *parent)
        :   QQuickItem(parent)
    {
        m_systemTray = new QSystemTrayIcon(this);
        connect(m_systemTray, &QSystemTrayIcon::activated, this, &SystemTrayIcon::onActivated);
        connect(this, &SystemTrayIcon::visibleChanged, this, &SystemTrayIcon::onVisibleChanged);
        setVisible(false);              //给visible一个初始值，否则会不显示
    }
    
    SystemTrayIcon::~SystemTrayIcon()
    {
    
    }
    
    int SystemTrayIcon::x() const
    {
        return m_systemTray->geometry().x();
    }
    
    int SystemTrayIcon::y() const
    {
        return m_systemTray->geometry().y();
    }
    
    QUrl SystemTrayIcon::icon() const
    {
        return m_icon;
    }
    
    QString SystemTrayIcon::toolTip() const
    {
        return m_systemTray->toolTip();
    }
    
    MyMenu *SystemTrayIcon::menu() const
    {
        return m_menu;
    }
    
    void SystemTrayIcon::setIcon(const QUrl &arg)
    {
        if(m_icon != arg)
        {
            QString str = arg.toLocalFile();
            if(str == "") str = arg.toString(); //如果转换失败
            if( str.mid (0, 3) == "qrc")
                str = str.mid (3, str.count() - 3);
            m_systemTray->setIcon(QIcon(str));
            m_icon = arg;
            emit iconChanged();
        }
    }
    
    void SystemTrayIcon::setToolTip(const QString &arg)
    {
        if (m_toolTip != arg)
        {
            m_systemTray->setToolTip(arg);
            m_toolTip = arg;
            emit toolTipChanged();
        }
    }
    
    void SystemTrayIcon::setMenu(MyMenu *arg)    //设置托盘上下文菜单
    {
        if (m_menu != arg)
        {
            m_menu = arg;
            m_systemTray->setContextMenu(m_menu->m_menu);
            m_systemTray->installEventFilter(this);
            emit menuChanged();
        }
    }
    
    void SystemTrayIcon::onVisibleChanged()    //visible可见性改变时显示/隐藏托盘
    {
        m_systemTray->setVisible(isVisible());
    }
    
    void SystemTrayIcon::onActivated(QSystemTrayIcon::ActivationReason reason)
    {
        switch (reason)
        {
        case QSystemTrayIcon::DoubleClick:
        case QSystemTrayIcon::Trigger:
            emit trigger();            //单击双击托盘图标时发送trigger()信号, reason类似还有Context,MiddleClick,Unknow
    
        default:
            break;
        }
    }
    
    void SystemTrayIcon::onExit()    //应在程序退出时调用，防止图标不消失
    {
        m_systemTray->hide();
        QApplication::exit(0);
    }

main.cpp

#include <QApplication>
    #include <QQmlApplicationEngine>
    #include "systemtrayicon.h"
    
    int main(int argc, char *argv[])
    {
        QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
        QApplication app(argc, argv);
    
        QQmlApplicationEngine engine;
        qmlRegisterType<MyMenu>("an.utility", 1, 0, "MyMenu");        //注册到qml中
        qmlRegisterType<MyAction>("an.utility", 1, 0, "MyAction");
        qmlRegisterType<MySeparator>("an.utility", 1, 0, "MySeparator");
        qmlRegisterType<SystemTrayIcon>("an.utility", 1, 0, "SystemTrayIcon");
        engine.load(QUrl(QLatin1String("qrc:/main.qml")));
        if (engine.rootObjects().isEmpty())
            return -1;
    
        return app.exec();
    }

--------------------

### **【结语】** ###

好吧，还有很多地方没有完善，比如快捷键。

其实写自定义组件和写 widget 差不多。。不过写好之后，在qml中使用起来就非常方便了。

当然，最后我自己试了试 Qt.labs.platform 1.0 中的 SystemTrayIcon，嗯基本上差不多吧。。所以期待以后的版本正式加入咯。

[20180404100650676]: /images/20220528/2357721043cb4629a2540c7472081cb9.png