The program will easily break down if I use QSortFilterProxyModel to help sort

[JKSH]

@uuutty Run your program in a debugger. When it crashes, show us your stack trace.

[jsulm]

@uuutty In timerUpDate you're modifying proShowInfoList and in data() you're accessing proShowInfoList using [] - most probably that's the problem (row does not exist in the list: proShowInfoList[row]). You need to check whether row < proShowInfoList.size().

[uuutty]

@jsulm I add

if (row >= proShowInfoList.length())
    {
        return QVariant();
    }

into my my function but the problem still exists. Even thoughI do nothing, directly return from my data function.

@JKSH

Is this what you want?

[JKSH]

@uuutty said in The program will easily break down if I use QSortFilterProxyModel to help sort:

@JKSH ...
Is this what you want?

Yep, that's the stack trace. Unfortunately, we cannot see the full names in the "Function" column.

Generate that stack trace again, and then Right-Click -> "Copy Contents to Clipboard", and then paste the text here (you don't need to post a picture)

[uuutty]

@JKSH

0	QSortFilterProxyModel::parent(QModelIndex const&) const			0xb6e67fe6	
1	QPersistentModelIndex::parent() const			0xb6e3c298	
2	??			0xb6e55970	
3	QItemSelection::merge(QItemSelection const&, QFlags<QItemSelectionModel::SelectionFlag>)			0xb6e4fb76	
4	QItemSelectionModel::columnIntersectsSelection(int, QModelIndex const&) const			0xb6e505c4	
5	??			0xb7ba26be	
6	QHeaderView::paintSection(QPainter *, QRect const&, int) const			0xb7ba144e	
7	QHeaderView::paintEvent(QPaintEvent *)			0xb7b9a86b	
8	QWidget::event(QEvent *)			0xb7953e7a	
9	QFrame::event(QEvent *)			0xb7a5ebda	
10	QAbstractScrollArea::viewportEvent(QEvent *)			0xb7aec252	
11	QAbstractItemView::viewportEvent(QEvent *)			0xb7b928f0	
12	QHeaderView::viewportEvent(QEvent *)			0xb7ba0b3a	
13	??			0xb7aecd43	
14	QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject *, QEvent *)			0xb6e9a55f	
15	QApplicationPrivate::notify_helper(QObject *, QEvent *)			0xb790def8	
16	QApplication::notify(QObject *, QEvent *)			0xb7913464	
17	QCoreApplication::notifyInternal(QObject *, QEvent *)			0xb6e9a787	
18	QWidgetPrivate::sendPaintEvent(QRegion const&)			0xb794c5e6	
19	QWidgetPrivate::drawWidget(QPaintDevice *, QRegion const&, QPoint const&, int, QPainter *, QWidgetBackingStore *)			0xb794cc3d	
20	??			0xb791ba9d	
21	??			0xb791bee6	
22	QWidgetPrivate::syncBackingStore()			0xb793d9c1	
23	QWidget::event(QEvent *)			0xb7953ebc	
24	QMainWindow::event(QEvent *)			0xb7a7689f	
25	QApplicationPrivate::notify_helper(QObject *, QEvent *)			0xb790df1a	
26	QApplication::notify(QObject *, QEvent *)			0xb7913464	
27	QCoreApplication::notifyInternal(QObject *, QEvent *)			0xb6e9a787	
28	QCoreApplicationPrivate::sendPostedEvents(QObject *, int, QThreadData *)			0xb6e9cc1d	
29	QCoreApplication::sendPostedEvents(QObject *, int)			0xb6e9d2f7	
30	??			0xb6ef19b3	
31	g_main_context_dispatch			0xb668fe29	
32	??			0xb66900c9	
33	g_main_context_iteration			0xb6690194	
34	QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)			0xb6ef1da4	
35	??			0xb446ce21	
36	QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)			0xb6e97d13	
37	QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>)			0xb6e9818a	
38	QCoreApplication::exec()			0xb6ea028a	
39	QGuiApplication::exec()			0xb722ba81	
40	QApplication::exec()			0xb7909ab4	
41	main	main.cpp	20	0x8052880	

[VRonin]

since you reset the model inside timerUpDate you need to signal the operation with beginResetModel() and endResetModel() http://doc.qt.io/qt-5/qabstractitemmodel.html#beginResetModel

[uuutty]

@VRonin Thanks a lot! Does this like a semaphore in something need mutual exclusion?

[VRonin]

@uuutty I don't think I get your question... are you multi threading at the model level?

[uuutty]

@VRonin I probably use the incorrect word. I mean do the beginResetModel() and endResetModel() help to prevent QSortFilterProxyModel or view read from proShowInfoList when I change it.

[uuutty]

@VRonin By the way, how can I mark you answer as a correct answer, I find I can just mark my post as a correct answer.