从C++更改QML图像源

class ImageController : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString imageSource READ imageSource WRITE setImageSource NOTIFY imageSourceChanged)

public:
    QString imageSource() const;
    void setImageSource(const QString& source);

signals:
    void imageSourceChanged();

private:
    QString m_imageSource;
};

QString ImageController::imageSource() const
{
    return m_imageSource;
}

void ImageController::setImageSource(const QString& source)
{
    if (m_imageSource != source) {
        m_imageSource = source;
        emit imageSourceChanged();
    }
}

QQmlApplicationEngine engine;
ImageController imageController;
engine.rootContext()->setContextProperty("ImageController", &imageController);
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

import QtQuick 2.0

Image {
    source: ImageController.imageSource
    // 其他属性设置
}

imageController.setImageSource("path/to/image.png");