c++ - QDeclarativeImageProvider 不在容器中加载图像

Question

Image {
        id: backImage
        source: "image://imageprovider/frontimage"
    }

工作正常，但不适用于 Column 或其他容器

Column {

    Image {
            id: backImage
            source: "image://imageprovider/frontimage"
        }
}

鉴于

Column {

    Image {
            id: backImage
            source: "screen1.png"
        }
}

好的。为什么？

声明:

class QMLImageProvider : public QObject, public QDeclarativeImageProvider
{
    Q_OBJECT
private:
    QPixmap front;
    QPixmap back;

public:
    explicit QMLImageProvider();
    QPixmap requestPixmap(const QString &id, QSize *size, const QSize &requestedSize);
};

实现:

QMLImageProvider::QMLImageProvider() : QObject(0),
        QDeclarativeImageProvider(QDeclarativeImageProvider::Pixmap) {}

QPixmap QMLImageProvider::requestPixmap(const QString &id, QSize *size, const QSize &requestedSize) {
    return QPixmap(QString("QML/screen1.png"));
}

注册:

screenArea = new QDeclarativeView(wgScreenArea);
    qmlImageProvider = new QMLImageProvider();
    screenArea->engine()->addImageProvider(GlobalVars::imageProviderID, qmlImageProvider);

    screenArea->setSource(QUrl::fromLocalFile("QML/screen.qml"));
    screenArea->setResizeMode(QDeclarativeView::SizeRootObjectToView);

附言对不起我的英语。

~已解决~

Column {
    id:screenImage
    Image {
        id: backImage
        width: screenImage.width
        height: screenImage.height
        source: "image://imageprovider/backimage"
    }
}

有效!非常感谢!

Answer 1

可能是 Image 使用 ImageProvider 没有正确声明它的宽度和高度？ Column 对于未声明其宽度和高度的项目来说有点滑稽。尝试在第二个示例的 Image 中对 width 和 height 进行硬编码，它应该可以工作。