c++ - Qt:在默认浏览器中打开带有目标的链接，不会泄漏内存

Question

通过 Internet 搜索，我遇到了很多使用 QWebView 和打开 URL 来做各种事情的方法，其中大部分是非功能性的、非特定的或部分功能性的。

经过多次咒骂和诅咒，我设法得到一个例子来做我想做的事，正常打开普通链接，并在外部浏览器中打开任何请求新窗口的东西；但是，有一个障碍。它会泄漏内存，因为我做了一堆额外的 WebViews，直到进程退出才被清理。如何在不泄漏内存的情况下执行此操作？

请提前原谅我对Qt的浅薄理解。目前我只使用了几个小时。

中南合作:

测试.hpp

#include <QMainWindow>
#include <QWebView>

class Window : public QMainWindow {
  Q_OBJECT

public:
  Window();

private:
  QWebView* m_web;

private slots:
};

class WebPage : public QWebPage {
  Q_OBJECT

public:
    bool acceptNavigationRequest(QWebFrame *frame, const QNetworkRequest &request, NavigationType type);
};

class WebView : public QWebView {
  Q_OBJECT

public:
  QWebView* createWindow(QWebPage::WebWindowType type);
};

测试.cpp

#include <QApplication>
#include <QGridLayout>
#include <QNetworkRequest>
#include <QDesktopServices>

#include "test.hpp"

Window::Window() :
    QMainWindow() {
  m_web = new WebView;
  m_web->setHtml("<div align=\"center\"><a href=\"http://www.google.com/\">Same Window</a> <a href=\"http://www.google.com/\" target=\"_blank\">New Window</a></div>");

  setCentralWidget(m_web);
}

bool WebPage::acceptNavigationRequest(QWebFrame*, QNetworkRequest const& request, NavigationType) {
  QDesktopServices::openUrl(request.url());
  return false;
}

QWebView* WebView::createWindow(QWebPage::WebWindowType) {
  auto res = new WebView;
  auto page = new WebPage;
  res->setPage(page);
  return res;
}

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

  Window w;
  w.show();

  return a.exec();
}

测试.pro

QT += core gui network webkitwidgets widgets

TEMPLATE = app
TARGET = test
INCLUDEPATH += .

CONFIG += c++11

# Input
SOURCES += test.cpp
HEADERS += test.hpp

编译运行

qmake test.pro
make
./test

Answer 1

在外部浏览器中呈现页面后， View 似乎变得无用。您可能只是安排使用 deleteLater() 删除 ExternalWebView:

#include <iostream>

#include <QApplication>
#include <QGridLayout>
#include <QNetworkRequest>
#include <QDesktopServices>

#include <QEvent>
#include <QMainWindow>
#include <QWebView>

class ExternWebPage : public QWebPage {
    //Q_OBJECT

    public:
    ExternWebPage(QObject* parent = 0)
    :   QWebPage(parent)
    {
        std::cout << "ExternWebPage" << std::endl;
    }

    ~ExternWebPage() {
        std::cout << "Destroy ExternWebPage" << std::endl;
    }

    virtual bool event(QEvent *e) {
        static unsigned counter;
        std::cout << ++counter << " ExternWebPage: " << e->type() << std::endl;
        return QWebPage::event(e);
    }

    bool acceptNavigationRequest(QWebFrame *, const QNetworkRequest &request, NavigationType) {
        QDesktopServices::openUrl(request.url());
        return false;
    }
};


class ExternWebView : public QWebView {
    //Q_OBJECT

    public:
    ExternWebView(QWidget* parent = 0)
    :   QWebView(parent)
    {
        std::cout << "ExternWebView" << std::endl;
    }
    ~ExternWebView() { std::cout << "Destroy ExternWebView" << std::endl; }
    virtual bool event(QEvent *e) {
        static unsigned counter;
        std::cout << ++counter << " ExternWebView: " << e->type() << std::endl;
        return QWebView::event(e);
    }
};


class InternalWebView : public QWebView {
    //Q_OBJECT

    public:
    InternalWebView(QWidget* parent = 0)
    :   QWebView(parent)
    {}
    QWebView* createWindow(QWebPage::WebWindowType) {
        auto res = new ExternWebView();
        res->setPage(new ExternWebPage(res));
        res->deleteLater();
        return res;
    }
};


class Window : public QMainWindow {
    //Q_OBJECT

    public:
    Window()
    :   QMainWindow()
    {
        std::cout << "Window" << std::endl;
        auto web = new InternalWebView(this);
        web->setHtml("<div align=\"center\"><a href=\"http://www.google.com/\">Same Window</a> <a href=\"http://www.google.com/\" target=\"_blank\">New Window</a></div>");
        setCentralWidget(web);
    }
    ~Window() { std::cout << "Destroy Window" << std::endl; }

};


int main(int argc, char *argv[]) {
  QApplication a(argc, argv);
  Window w;
  w.show();
  return a.exec();
}

不删除测试:

Window
ExternWebView
1 ExternWebView: 68
ExternWebPage
2 ExternWebView: 74
3 ExternWebView: 75
1 ExternWebPage: 43
2 ExternWebPage: 43
3 ExternWebPage: 43
4 ExternWebPage: 43
5 ExternWebPage: 43
Destroy Window

稍后删除测试:

ExternWebView
1 ExternWebView: 68
ExternWebPage
2 ExternWebView: 74
3 ExternWebView: 75
4 ExternWebView: 52
Destroy ExternWebView
Destroy ExternWebPage
Destroy Window