QWebEngine：删除 QWebEngineUrlRequestInterceptor 导致崩溃

Question

在我的项目中，我想 create/delete QWebEnginePages 当 opening/closing 一个应用程序。使用 Qt5.9.7 一切正常。切换到 Qt5.12.6 时，我的应用程序会崩溃。

我创建了一个小代码示例，我只需单击一个按钮即可创建和删除。当然，在我的真实项目中，我确保一切都受到保护等：

BrowserWidget::BrowserWidget(QWidget *parent)
    : QWidget(parent), ui(new Ui::Widget) {
  m_webView = new QWebEngineView(this);

  ui->setupUi(this);
  ui->verticalLayout->addWidget(m_webView);

  connect(ui->createBtn, &QPushButton::clicked, this,
          &BrowserWidget::createSession);
  connect(ui->deleteBtn, &QPushButton::clicked, this,
          &BrowserWidget::deleteSession);
}

BrowserWidget::~BrowserWidget() {
  delete ui;
}

void BrowserWidget::createSession() {
  m_page = new QWebEnginePage(this);
  m_interceptor = new UrlRequestInterceptor(this);
  m_page->profile()->setRequestInterceptor(m_interceptor);

  for (auto c : m_connections) {
    disconnect(c);
  }
  m_connections.clear();

  m_page->setUrl(
      QUrl(QStringLiteral("https://www.youtube.com/watch?v=rNSnfXl1ZjU")));
  m_webView->setPage(m_page);

  return;
}

void BrowserWidget::deleteSession() {
  delete m_page;
  delete m_interceptor; // This causes the crash
}

整个UrlRequestInterceptor.cpp看起来像这样：

UrlRequestInterceptor::UrlRequestInterceptor(QObject *parent)
    : QWebEngineUrlRequestInterceptor(parent) {}

void UrlRequestInterceptor::interceptRequest(QWebEngineUrlRequestInfo &info) {
  info.block(false);
  return;
}

当我快速打开和关闭 "WebPages" 时，delete m_interceptor 会导致崩溃。当网页完全加载时，有时也会发生这种情况，但并不经常发生。我在文档中找不到任何相关信息。

你们中有人知道我如何才能可靠地等待所有 interceptor/browser-related 内容完成后再删除 m_interceptor 吗？

这是有用的堆栈跟踪：

1   QtWebEngineCore::CustomProtocolHandler::MaybeCreateJob          Qt5WebEngineCored  0x7ffd06bdd708 
2   QtWebEngineCore::CookieMonsterDelegateQt::hasCookieMonster      Qt5WebEngineCored  0x7ffd0a4aa0ae 
3   QtWebEngineCore::CookieMonsterDelegateQt::hasCookieMonster      Qt5WebEngineCored  0x7ffd0a4b1ca5 
4   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094b5a12 
5   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094b4a01 
6   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094b0769 
7   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094b5777 
8   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094a83c8 
9   QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094a078f 
10  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094a34ca 
11  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd0949ffdf 
12  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094a65c5 
13  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094a67af 
14  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094c15d3 
15  QWebEngineCookieStorePrivate::q_func                            Qt5WebEngineCored  0x7ffd0b93f07d 
16  QtWebEngineCore::WebContentsAdapter::webContents                Qt5WebEngineCored  0x7ffd094b91bb 
17  QtWebEngineCore::JavaScriptDialogController::qt_static_metacall Qt5WebEngineCored  0x7ffd06db6c45 
18  QWebEngineQuotaRequest::QWebEngineQuotaRequest                  Qt5WebEngineCored  0x7ffd08ea7a85 
19  QtWebEngineCore::FilePickerController::mode                     Qt5WebEngineCored  0x7ffd0a1c5e75 
20  QtWebEngineCore::FilePickerController::mode                     Qt5WebEngineCored  0x7ffd0a1c4a31

非常感谢！

Answer 1

我认为您真的不需要在每次启动会话时都创建一个新的拦截器实例。在你的 BrowserWidget class:

中只有一个实例

private:
    Ui::BrowserWidget *ui;
    UrlRequestInterceptor m_interceptor;

在小部件构造函数中初始化它：

BrowserWidget::BrowserWidget(QWidget *parent)
    : QWidget(parent), ui(new Ui::BrowserWidget), m_interceptor(this)

将指向它的指针传递给页面配置文件：

void BrowserWidget::createSession() {
  m_page = new QWebEnginePage(this);
  m_page->profile()->setRequestInterceptor(&m_interceptor);

去掉deleteSession中的delete:

void BrowserWidget::deleteSession() {

  delete m_page;
//  delete m_interceptor; // This (no more) causes the crash
}

QWebEngine：删除 QWebEngineUrlRequestInterceptor 导致崩溃

QWebEngine: deleting QWebEngineUrlRequestInterceptor results in crash

c++

qt

qtwebengine

qt5.9

qt5.12