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 importQtQuick1.x或 importQtQuick2.x;
  

1. 
   equals(QT_MAJOR_VERSION,4){
   
2. 
      equals(QT_MINOR_VERSION,7): QT_QUICK_VERSION =1.0
   
3. 
      equals(QT_MINOR_VERSION,8): QT_QUICK_VERSION =1.1
   
4. 
   }
   


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


6. 
   macx {
   
7. 
      !isEmpty(QT_QUICK_VERSION):
   
8. 
      QtQuickVersion.commands +=
   
9. 
      "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i '' 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
   
10. 
    }
    


11. 
    unix:!macx {
    
12. 
       !isEmpty(QT_QUICK_VERSION):
    
13. 
       QtQuickVersion.commands +=
    
14. 
       "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
    
15. 
    }
    


16. 
    QtQuickVersion.target = FORCE
    


17. 
    PRE_TARGETDEPS += FORCE
    
18. 
    QMAKE_EXTRA_TARGETS +=QtQuickVersion
    

pro文件

1. 
   QT += core
   


2. 
   equals (QT_MAJOR_VERSION,4): QT += declarative
   


3. 
   equals (QT_MAJOR_VERSION,5): QT += qml quick quickwidgets
   


4. 
   SOURCES += main.cpp
   


5. 
   equals(QT_MAJOR_VERSION,4){
   
6. 
      equals(QT_MINOR_VERSION,7): QT_QUICK_VERSION =1.0
   
7. 
      equals(QT_MINOR_VERSION,8): QT_QUICK_VERSION =1.1
   
8. 
   }
   


9. 
   equals(QT_MAJOR_VERSION,5): QT_QUICK_VERSION =2.$${QT_MINOR_VERSION}
   


10. 
    macx {
    
11. 
       !isEmpty(QT_QUICK_VERSION):
    
12. 
       QtQuickVersion.commands +=
    
13. 
       "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i '' 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
    
14. 
    }
    


15. 
    unix:!macx {
    
16. 
       !isEmpty(QT_QUICK_VERSION):
    
17. 
       QtQuickVersion.commands +=
    
18. 
       "grep -rl 'QtQuick [0-9]\\.[0-9]' $$PWD/ | xargs sed -i 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
    
19. 
    }
    


20. 
    QtQuickVersion.target = FORCE
    


21. 
    PRE_TARGETDEPS += FORCE
    
22. 
    QMAKE_EXTRA_TARGETS +=QtQuickVersion
    

main.cpp

1. 
   #include<QtGlobal>
   
2. 
   #if (QT_VERSION < QT_VERSION_CHECK(5, 0, 0))
   


3. 
   #include<QApplication>
   
4. 
   #include<QDeclarativeView>
   


5. 
   int main(int argc,char*argv[])
   
6. 
   {
   
7. 
      QApplication app(argc, argv);
   


8. 
      QDeclarativeView viewer;
   
9. 
      viewer.setSource(QUrl::fromLocalFile(QLatin1String("main.qml")));
   
10. 
       viewer.show();
    
11. 
       return app.exec();
    
12. 
    }
    


13. 
    #else
    


14. 
    #include<QApplication>
    
15. 
    #include<QQuickView>
    


16. 
    int main(int argc,char*argv[])
    
17. 
    {
    
18. 
       QApplication app(argc, argv);
    


19. 
       QQuickView viewer;
    
20. 
       viewer.setSource(QUrl::fromLocalFile(QLatin1String("main.qml")));
    
21. 
       viewer.show();
    
22. 
       return app.exec();
    
23. 
    }
    


24. 
    #endif
    

Qt4版本编译替换后的main.qml

1. 
   importQtQuick1.1
   


2. 
   Rectangle{
   
3. 
      width:360
   
4. 
      height:360
   
5. 
      Text{
   
6. 
          text: qsTr("Hello World")
   
7. 
          anchors.centerIn: parent
   
8. 
      }
   
9. 
      MouseArea{
   
10. 
           anchors.fill: parent
    
11. 
           onClicked:{
    
12. 
               Qt.quit();
    
13. 
           }
    
14. 
       }
    
15. 
    }
    

Qt5版本编译替换后的main.qml

1. 
   importQtQuick2.7
   


2. 
   Rectangle{
   
3. 
      width:360
   
4. 
      height:360
   
5. 
      Text{
   
6. 
          text: qsTr("Hello World")
   
7. 
          anchors.centerIn: parent
   
8. 
      }
   
9. 
      MouseArea{
   
10. 
           anchors.fill: parent
    
11. 
           onClicked:{
    
12. 
               Qt.quit();
    
13. 
           }
    
14. 
       }
    
15. 
    }
    

源码地址

1. 
   https://github.com/aeagean/QtQuickDemo.git