qt - Qt WebEngineView 渲染空图像

Question

我正在使用 qt 5.6.2。我想在网页上截屏。这是我正在使用的代码：

#include <QtWidgets/QApplication>
#include <QtWebEngineWidgets/QWebEngineView>

int main(int argc, char *argv[]){
    int left, top, width, height;
    left = 0;
    top = 0;
    width = 600;
    height = 800;

    QApplication a(argc, argv);
    QWebEngineView* w = new QWebEngineView();
    QImage image(height, width, QImage::Format_RGB32);
    QRegion rg(left, top, width, height);
    QPainter painter(&image);
    w->page()->load(QUrl("https://www.yahoo.com"));
    w->show();
    w->page()->view()->render(&painter, QPoint(), rg);
    painter.end();
    image.save("test.png", "PNG", 80);

    return a.exec();
}

我运行程序，出现一个窗口，我可以看到yahoo. 然后我将结果保存到test.png但那是一张白色的图片。是我无法将结果image保存到文件还是无法将结果保存image到文件test.png以及如何解决？

Answer 1

You need to wait for the page to finish loading.

QWebEngineView* w = new QWebEngineView();
w->page()->load(QUrl("https://www.yahoo.com"));
w->show();


QObject::connect(w, &QWebEngineView::loadFinished,
                 [w](bool bOk)
{
    int left, top, width, height;
    left = 0;
    top = 0;
    width = 600;
    height = 800;

    QImage image(height, width, QImage::Format_RGB32);
    QRegion rg(left, top, width, height);
    QPainter painter(&image);
    w->page()->view()->render(&painter, QPoint(), rg);
    painter.end();
    image.save("test.png", "PNG", 80);
});