如何从qwebengineview中提取数据qt5.9

#include <QApplication>
#include <QWebEngineView>
#include <QWebEnginePage>
#include <QWebEngineProfile>
#include <QWebEngineSettings>
#include <QWebEngineScript>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QWebEngineView view;
    view.settings()->setAttribute(QWebEngineSettings::JavascriptEnabled, true);
    view.load(QUrl("https://www.example.com"));

    QObject::connect(&view, &QWebEngineView::loadFinished, [&view]() {
        QWebEnginePage* page = view.page();

        // 注册JavaScript代码
        QString script = R"(
            // 在这里编写提取数据的JavaScript代码
            var data = document.querySelector('selector').innerText;
            data;
        )";

        QWebEngineScript webScript;
        webScript.setSourceCode(script);
        webScript.setInjectionPoint(QWebEngineScript::DocumentReady);
        webScript.setWorldId(QWebEngineScript::MainWorld);
        page->scripts().insert(webScript);

        // 提取数据
        page->runJavaScript(script, [page](const QVariant &result) {
            // 处理提取的数据
            QString data = result.toString();
            // ...
        });
    });

    view.show();

    return a.exec();
}