QMap<QString, CLogin::AccountInfo>::iterator iter; for (iter = m_pLogin->getAccountMgr().begin(); iter != m_pLogin->getAccountMgr().end(); ++iter) { UpdateTableWidget(iter); } void wLoginMgr::UpdateTableWidget(QMap<QString, CLogin::AccountInfo>::iterator iter) { int nIndex = this->ui.tableWidget->rowCount(); this->ui.tableWidget->insertRow(nIndex); QTableWidgetItem* itemID = new QTableWidgetItem(iter.key()); QTableWidgetItem* itemAuth = new QTableWidgetItem(m_pLogin->EnumtoQString(iter.value().eAuthority)); QTableWidgetItem* itemDate = new QTableWidgetItem(iter.value().createDate.toString(m_pLogin->getDateFormat())); itemID->setTextAlignment(Qt::AlignCenter); itemAuth->setTextAlignment(Qt::AlignCenter); itemDate->setTextAlignment(Qt::AlignCenter); this->ui.tableWidget->setItem(nIndex, 0, itemID); this->ui.tableWidget->setItem(nIndex, 1, itemAuth); this->ui.tableWidget->setItem(nIndex, 2, itemDate); } I'm writing an example that puts items in a tableWidget using qmap iterator, but I can't access it with iter, so I ask a question. Exception handling occurs the moment iter is accessed. If I use Qmapiterator inside the m_pLogin class, it works as well. It doesn't seem to work when accessing from the outside. Is there a workaround:?

C++ stuff m_pLogin->getAccountMgr().begin() m_pLogin->getAccountMgr().end() You're creating two temporary container here which are out-of-scope so your program will crash.

@ IknowQT said in QMap iterator Bug?? : I think this topic is endless. Can you post some concrete example code? You already have it and you even wrote that it is working...

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QMap iterator Bug??

Solved General and Desktop

21 Posts 5 Posters 2.8k Views

J JoeCFD

@KroMignon said in QMap iterator Bug??:

@JoeCFD said in QMap iterator Bug??:

I believe std containers may be better optimized than Qt containers in most cases.

Not according to this benchmark done by woboq => https://woboq.com/blog/qmap_qhash_benchmark.html <=== done in 2012 ages old.
or this stackoverflow entry => https://stackoverflow.com/questions/1668259/stl-or-qt-containers read comments: 35
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Christian Ehrlicher
Lifetime Qt Champion
wrote on last edited by Christian Ehrlicher

#21

@JoeCFD When you're at the point where you really need to worry about a speed difference between those implementations you should write your own implementation of the problematic container. You will never notice if a running program is using c++ or Qt or boost or whatever containers.
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