兼容Qt4/Qt5版本的QML例程

本篇文章介绍兼容Qt4与Qt5版本的Qml简单例程。由于Qt4与Qt5版本的qml文件不能使用宏来区分，所以使用qmake执行脚本来修改qml版本差异代码。(末尾源代码地址)

qml文件转换

• 下列代码是项目文件代码，会在编译之前执行;
• 主要作用为识别Qt版本然后替换对应qml文件中的import QtQuick 1.x或import QtQuick 2.x;

equals(QT_MAJOR_VERSION, 4) {
    equals(QT_MINOR_VERSION, 7): QT_QUICK_VERSION = 1.0
    equals(QT_MINOR_VERSION, 8): QT_QUICK_VERSION = 1.1
}

equals(QT_MAJOR_VERSION, 5): QT_QUICK_VERSION = 2.$${QT_MINOR_VERSION}

macx {
    !isEmpty(QT_QUICK_VERSION): 
    QtQuickVersion.commands += 
    "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i '' 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
}

unix:!macx {
    !isEmpty(QT_QUICK_VERSION): 
    QtQuickVersion.commands += 
    "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
}

QtQuickVersion.target = FORCE

PRE_TARGETDEPS += FORCE
QMAKE_EXTRA_TARGETS += QtQuickVersion

pro文件

QT += core

equals (QT_MAJOR_VERSION, 4): QT += declarative

equals (QT_MAJOR_VERSION, 5): QT += qml quick quickwidgets

SOURCES += main.cpp

equals(QT_MAJOR_VERSION, 4) {
    equals(QT_MINOR_VERSION, 7): QT_QUICK_VERSION = 1.0
    equals(QT_MINOR_VERSION, 8): QT_QUICK_VERSION = 1.1
}

equals(QT_MAJOR_VERSION, 5): QT_QUICK_VERSION = 2.$${QT_MINOR_VERSION}

macx {
    !isEmpty(QT_QUICK_VERSION): 
    QtQuickVersion.commands += 
    "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i '' 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
}

unix:!macx {
    !isEmpty(QT_QUICK_VERSION): 
    QtQuickVersion.commands += 
    "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
}

QtQuickVersion.target = FORCE

PRE_TARGETDEPS += FORCE
QMAKE_EXTRA_TARGETS += QtQuickVersion

main.cpp

#include <QtGlobal>
#if (QT_VERSION < QT_VERSION_CHECK(5, 0, 0))

#include <QApplication>
#include <QDeclarativeView>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QDeclarativeView viewer;
    viewer.setSource(QUrl::fromLocalFile(QLatin1String("main.qml")));
    viewer.show();
    return app.exec();
}

#else

#include <QApplication>
#include <QQuickView>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QQuickView viewer;
    viewer.setSource(QUrl::fromLocalFile(QLatin1String("main.qml")));
    viewer.show();
    return app.exec();
}

#endif

Qt4版本编译替换后的main.qml

import QtQuick 1.1

Rectangle {
    width: 360
    height: 360
    Text {
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }
    MouseArea {
        anchors.fill: parent
        onClicked: {
            Qt.quit();
        }
    }
}

Qt5版本编译替换后的main.qml

import QtQuick 2.7

Rectangle {
    width: 360
    height: 360
    Text {
        text: qsTr("Hello World")
        anchors.centerIn: parent
    }
    MouseArea {
        anchors.fill: parent
        onClicked: {
            Qt.quit();
        }
    }
}

源码地址

https://github.com/aeagean/QtQuickDemo.git