how to update widget in main ui from future work?

[benlau]

how to update widget in main ui from future work?

[vpicaver]

I guess you could do this but I would suggest allocating QWidgets on the main thread instead. It seems inefficient and odd that you're creating and using 50000 plots. Also accessing ui isn't thread safe and you'll likely have undefined behaviour.

QObjects have thread affinity. For you code to work you need to push the newly created QWidgets to the main thread QObject::moveToThread(QCoreApplication::instance()->thread()). Then you need to call anotherwdtlay->addWidget(plot) in the main thread.

[xkungfu]

I guess you could do this but I would suggest allocating QWidgets on the main thread instead. It seems inefficient and odd that you're creating and using 50000 plots. Also accessing ui isn't thread safe and you'll likely have undefined behaviour.

QObjects have thread affinity. For you code to work you need to push the newly created QWidgets to the main thread QObject::moveToThread(QCoreApplication::instance()->thread()). Then you need to call anotherwdtlay->addWidget(plot) in the main thread.

I have payed two week to understand your answer. you are very right, I am now try to do as you said!
thank you very much!

[vpicaver]

@xkungfu you should close this issue.