Question

我打算用QML创建一个应用程序。我在c ++中实现了很多qt小部件。 c ++小部件应该在QML中使用。

如何整合它们？ - 通往dlls的路径 - 是否存在一些qml容器？

我没有找到这个问题的好文档

Answer 1

除非有问题的小部件有很多图形（可能是你有一个基于QGraphivsView的类），否则它是可能的，但不是可以实现的。如果您要引用的小部件是＆＃34;正常＆＃34; QWidgets，请不要尝试这样做，因为它比它的价值更麻烦。

您需要创建一个继承QQuickPaintedItem并覆盖几个方法的新类：

部首：

class QQmlWidget : public QQuickPaintedItem
{
    Q_OBJECT    
public:
    explicit QMLProfile(QWidget *internalWidget, QQuickItem *parent = 0) : QQuickPaintedItem(parent), internalWidget(internalWidget){}
    virtual ~QMLProfile();
    void paint(QPainter *painter) override;

protected:
    void mouseMoveEvent(QMouseEvent *event);
private:
    QWidget *internalWidget;
};

.cpp的：（下面的代码来自Subsurface代码，它在QML上使用QGraphivsView）

void paint(QPainter* painter) {
    // let's look at the intended size of the content and scale our scene accordingly
    QRect painterRect = painter->viewport();
    QRect profileRect = internalWidget->viewport()->rect();

    qreal sceneSize = 104; // that should give us 2% margin all around (100x100 scene)
    qreal dprComp =  devicePixelRatio() * painterRect.width() / profileRect.width();
    qreal sx = painterRect.width() / sceneSize / dprComp;
    qreal sy = painterRect.height() / sceneSize / dprComp;

    // next figure out the weird magic by which we need to shift the painter so the widget is shown
    int dpr = rint(devicePixelRatio());
    qreal magicShiftFactor = (dpr == 2 ? 0.25 : (dpr == 3 ? 0.33 : 0.0));

    // now set up the transformations scale the profile and
    // shift the painter (taking its existing transformation into account)
    QTransform profileTransform = QTransform();
    profileTransform.scale(sx, sy);
    QTransform painterTransform = painter->transform();
    painterTransform.translate(-painterRect.width() * magicShiftFactor ,-painterRect.height() * magicShiftFactor);

    // apply the transformation
    painter->setTransform(painterTransform);
    internalWidget->setTransform(profileTransform);

    // finally, render the profile
    internalWidget->render(painter);
}

QQmlWidget::mouseMoveEvent(QMouseEvent *ev){
     /* Map the eveent to the Widget */
     QQuickPaintedItem(ev);
     internalWidget->mouseEvent(ev);
}

正如我所说的那样，可行，但并非真正的直截了当。只有在无法在QML中重新创建小部件时才能这样做。

在qml中重用qt c ++小部件

1 个答案: