Calling library functions in Qt apps

With QtLibrary integrated with QtApp, you can now write code that uses the library's message() function.

To call a library method in QtApp code:
  1. Open main.cpp for editing (by double-clicking its entry under QtApp in the Project view), and replace its contents with this code:
    #include <QtGui/QGuiApplication>
    #include <QtQuick/QQuickView>
    #include <QScreen>
    #include <QQmlContext>
    #include "foo.h"
    int main(int argc, char *argv[])
        QGuiApplication app(argc, argv);
        // Get the screens so we can dynamically size our display
        QScreen* screen = QGuiApplication::primaryScreen();
        // Quit if there's no screen connected
        if (screen == NULL) {
            return 1;
        // Get the width and height of the display
        int w = screen->size().width();
        int h = screen->size().height();
        QQuickView view;
        Foo foo;
        QString msg = foo.message();
        view.rootContext()->setContextProperty("_message", msg);
        // Set up the view to have the proper size
        view.resize(w, h);
        return app.exec();
    The code in main.cpp uses the library by creating a Foo object, calling the object's message() function, and then making the returned string available to QML so it can be displayed.
  2. Open main.qml for editing and replace its contents with this code:
    import QtQuick 2.0
    Rectangle {
        Text {
            text: _message
            anchors.centerIn: parent
  3. Build the app by selecting Build > Build Project "QtApp".
The app is built with integrated QtLibrary functionality and can run on the target, so long as the library file is packaged with it.