C / QML项目兼容Qt 4（QtQuick 1.x）和Qt 5（QtQuick 2.x）

1 回答

• 3

  我所做的是在部署它们时替换所有QML文件中的字符串 QtQuick x.y . 如果源树中有一个文件夹 qml ，并且希望在构建树中具有相同的 qml 文件夹，则可以部署该文件夹，但替换该字符串以匹配所需的QtQuick版本 .

  以下解决方案适用于POSIX系统，因为它需要一些命令行工具;在Linux（Ubuntu）上测试过 . 也许具有Windows命令行经验的人可以为Windows添加版本 .

  Add in your .pro: （以下代码假定在构建文件夹中，使用 ../src/ 可以访问源文件夹;如果不是这种情况，请更改 *** 注释所在的路径）

  // Define QT5 macro for use in C++, and select the correct module for QML:
  greaterThan(QT_MAJOR_VERSION, 4) {
      DEFINES += QT5
      QT += quick
  } else {
      QT += declarative
  }
  
  // Define qmake variables for QtQuick version, and if you want, QtQuick Controls:
  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}
      equals(QT_MINOR_VERSION, 1): QT_QUICKCONTROLS_VERSION = 1.0
      equals(QT_MINOR_VERSION, 2): QT_QUICKCONTROLS_VERSION = 1.1
      equals(QT_MINOR_VERSION, 3): QT_QUICKCONTROLS_VERSION = 1.2
  }
  
  // Add a pre-build step which copies your qml folder
  QtQuickVersion.target = FORCE
  QtQuickVersion.commands = "rm -rf qml/;"
  QtQuickVersion.commands += "cp -r ../src/qml/ .;"  // <-- *** Here is the source path
  !isEmpty(QT_QUICK_VERSION) {
      QtQuickVersion.commands += "grep -rl 'QtQuick [0-9]\\.[0-9]' qml/ | xargs -r sed -i 's/QtQuick [0-9]\\.[0-9]/QtQuick $${QT_QUICK_VERSION}/g';"
  }
  !isEmpty(QT_QUICKCONTROLS_VERSION) {
      QtQuickVersion.commands += "grep -rl 'QtQuick.Controls [0-9]\\.[0-9]' qml/ | xargs -r sed -i 's/QtQuick.Controls [0-9]\\.[0-9]/QtQuick.Controls $${QT_QUICKCONTROLS_VERSION}/g';"
  }
  
  // Give the Makefile target *any* name which will *not* be created
  // as a file, so the step is always executed
  PRE_TARGETDEPS += FORCE
  QMAKE_EXTRA_TARGETS += QtQuickVersion
  

  In C++ (main.cpp) ，然后你可以为Qt 4创建一个 QQuickView ，它回落到 QDeclarativeView ：

  #ifdef QT5
  
  #include <QGuiApplication>
  #include <QQuickView>
  #include <QQmlEngine>
  
  #else
  
  #include <QApplication>
  #include <QDeclarativeView>
  #include <QDeclarativeEngine>
  typedef QApplication QGuiApplication;
  typedef QDeclarativeView QQuickView;
  // The following is the official fallback for QStringLiteral,
  // see qstring.h in Qt 5 after #ifndef QStringLiteral */
  #define QStringLiteral(str) QString::fromUtf8("" str "", sizeof(str) - 1)
  #endif
  
  
  int main(int argc, char *argv[])
  {
      QGuiApplication a(argc, argv);
  
      // (add qmlRegisterType etc.)
  
      // Open the QML view with the main QML document:
      QQuickView view;
      view.setSource(QUrl::fromLocalFile(QStringLiteral("qml/main.qml")));
      view.show();
  
      // Needed for "Qt.quit()" within QML:
      QObject::connect(view.engine(), SIGNAL(quit()), &a, SLOT(quit()));
  
      // I normally use this sizing behavior:
      view.setResizeMode(QQuickView::SizeRootObjectToView);
  
      return a.exec();
  }
  

  The QML file qml/main.qml 上面的代码打开后可以看起来像这样：

  // This import will replaced with the largest supported QtQuick version:
  import QtQuick 1.0
  
  Rectangle {
      width: 450
      height: 200
  
      Text {
          anchors.centerIn: parent
          horizontalAlignment: Text.AlignHCenter
          font.pointSize: Math.min(parent.width / 10, parent.height / 5)
  
          // This text will also be replaced to show the correct QtQuick version:
          text: "Hello from\nQtQuick 1.0!"
  
          // Some fancy animations...
          SequentialAnimation on scale {
              running: true; loops: Animation.Infinite
              NumberAnimation { from: 1; to: .6; easing.type: Easing.InOutQuad; duration: 600 }
              NumberAnimation { from: .6; to: 1; easing.type: Easing.InOutQuad; duration: 600 }
          }
          SequentialAnimation on rotation {
              running: true; loops: Animation.Infinite
              NumberAnimation { from: -10; to: 10; easing.type: Easing.InOutQuad; duration: 2000 }
              NumberAnimation { from: 10; to: -10; easing.type: Easing.InOutQuad; duration: 2000 }
          }
      }
  
      MouseArea {
          anchors.fill: parent
          onClicked: Qt.quit()
      }
  }
  

  QML文件包含一个import指令，它将选择正确的QtQuick版本（您可以在build文件夹中查看） . Text 元素中的字符串也会被替换，因此您将在此演示中轻松看到该版本 .

  回复于 2024-04-27T02:20:42+08:00