qtQuick源码中的loadImage函数答案

【问题标题】：loadImage function in qtQuick source codeqtQuick源码中的loadImage函数
【发布时间】：2017-10-17 15:58:16
【问题描述】：

在 qtQuick 源中。函数loadImage中有一行代码：

QQuickPixmap* pix = new QQuickPixmap();

如果我在canvas上尽量调用这个函数。操作系统分配给这个应用程序的内存会被填满，导致图片失效。请问有没有问题这个源代码？

void QQuickCanvasItem::loadImage(const QUrl& url)
{

    Q_D(QQuickCanvasItem);
    QUrl fullPathUrl = d->baseUrl.resolved(url);
    if (!d->pixmaps.contains(fullPathUrl)) {
        QQuickPixmap* pix = new QQuickPixmap();
        QQmlRefPointer<QQuickCanvasPixmap> canvasPix;
        canvasPix.adopt(new QQuickCanvasPixmap(pix));
        d->pixmaps.insert(fullPathUrl, canvasPix);

        pix->load(qmlEngine(this)
                , fullPathUrl
                , QQuickPixmap::Cache | QQuickPixmap::Asynchronous);
        if (pix->isLoading())
            pix->connectFinished(this, SIGNAL(imageLoaded()));
    }
}

【问题讨论】：

标签： c++ qt canvas qml qtquick2

【解决方案1】：

void QQuickCanvasItem::loadImage(const QUrl& url)
{

    Q_D(QQuickCanvasItem);
    QUrl fullPathUrl = d->baseUrl.resolved(url);
    if (!d->pixmaps.contains(fullPathUrl)) {
        QQuickPixmap* pix = new QQuickPixmap();
        QQmlRefPointer<QQuickCanvasPixmap> canvasPix;
        canvasPix.adopt(new QQuickCanvasPixmap(pix));
        d->pixmaps.insert(fullPathUrl, canvasPix);

        pix->load(qmlEngine(this)
                , fullPathUrl
                , QQuickPixmap::Cache | QQuickPixmap::Asynchronous);
        if (pix->isLoading())
            pix->connectFinished(this, SIGNAL(imageLoaded()));
    }
}

【讨论】：