我收到多个loadFinished当我尝试加载时发出信号QWebPage我不确定是什么导致了这个问题。还有其他几个问题似乎暗示了同一问题，但解决方案对我不起作用：
- QtWebPage - loadFinished() 多次调用 https://stackoverflow.com/questions/9966433/qtwebpage-loadfinished-called-multiple-times
-
信号 QWebPage::loadFinished(bool) 返回两次？ https://stackoverflow.com/questions/8415289/signal-qwebpageloadfinishedbool-returns-twice
在第一个问题中，答案是将信号连接到插槽一次，”但我已经这样做了。第二个问题的答案表明我应该连接到框架的loadFinished信号，但完成后我根本没有获得必要的数据。
我尝试加载多个页面：
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QList<QUrl> urls;
urls.append(QUrl("http://www.useragentstring.com/pages/Chrome/"));
urls.append(QUrl("http://www.useragentstring.com/pages/Firefox/"));
urls.append(QUrl("http://www.useragentstring.com/pages/Opera/"));
urls.append(QUrl("http://www.useragentstring.com/pages/Internet Explorer/"));
urls.append(QUrl("http://www.useragentstring.com/pages/Safari/"));
foreach(QUrl url, urls)
{
UA* ua = new UA();
QWebPage* page = new QWebPage();
//QObject::connect(page, SIGNAL(loadFinished(bool)), ua, SLOT(pageLoadFinished(bool)));
QObject::connect(page->mainFrame(), SIGNAL(loadFinished(bool)), ua, SLOT(frameLoadFinished(bool)));
// Load the page
page->mainFrame()->load(url);
}
return app.exec();
}
处理信号的类如下所示：
class UA:public QObject
{
Q_OBJECT
private:
int _numPageLoadSignals;
int _numFrameLoadSignals
public:
UA()
{
_numPageLoadSignals = 0;
_numFrameLoadSignals = 0;
}
~UA(){}
public slots:
void pageLoadFinished(bool ok)
{
_numPageLoadSignals++;
QWebPage * page = qobject_cast<QWebPage *>(sender());
if(ok && page)
{
qDebug() << _numPageLoadSignals << " loads "
<< page->mainFrame()->documentElement().findAll("div#liste ul li a").count()
<< " elements found on: " << page->mainFrame()->requestedUrl().toString();
}
}
void frameLoadFinished(bool ok)
{
_numFrameLoadSignals++;
QWebFrame * frame = qobject_cast<QWebFrame *>(sender());
if(ok && frame)
{
qDebug() << _numFrameLoadSignals << " loads "
<< frame->documentElement().findAll("div#liste ul li a").count()
<< " elements found on: " << frame->requestedUrl().toString();
}
}
};
这是仅连接到框架的结果loadFinished signal:
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Safari/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Chrome/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Opera/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Firefox/"
1 loads 241 elements found on: "http://www.useragentstring.com/pages/Internet Explorer/"
这是我连接到页面时的结果loadFinished signal:
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Safari/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Chrome/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Firefox/"
1 loads 0 elements found on: "http://www.useragentstring.com/pages/Internet Explorer/"
2 loads 576 elements found on: "http://www.useragentstring.com/pages/Safari/"
2 loads 782 elements found on: "http://www.useragentstring.com/pages/Chrome/"
2 loads 241 elements found on: "http://www.useragentstring.com/pages/Internet Explorer/"
2 loads 1946 elements found on: "http://www.useragentstring.com/pages/Firefox/"
3 loads 241 elements found on: "http://www.useragentstring.com/pages/Internet Explorer/"
3 loads 1946 elements found on: "http://www.useragentstring.com/pages/Firefox/"
3 loads 782 elements found on: "http://www.useragentstring.com/pages/Chrome/"
1 loads 964 elements found on: "http://www.useragentstring.com/pages/Opera/"
3 loads 576 elements found on: "http://www.useragentstring.com/pages/Safari/"
我不明白这种行为，为什么有时我得到相关内容，有时却得不到。如果我连接到页面的loadFinished信号，那么我最终会得到内容，但我不知道它什么时候会真正发生。我如何知道我的页面何时真正完成加载？
Update
我假设我的大部分内容将在 3 秒内到达，因此我想出了一个解决方法：我设置了一个计时器事件来发出信号UA::loadFinished第一个后 3 秒loadFinished信号是从接收到的QWebPage。这不是很漂亮，也不是高效的，但它适用于这种情况。
