Widgets must be created in the main thread error in Qt

Question

I have a problem in Qt.

I have a external pthread that need to show a Qt Dialog. I have created a class WindowsManager that contain a static function to show a Qt Dialog: WindowsManager::ShowDialog()

When call this function in my pthread

void* task(void*)
{
    WindowsManager::ShowDialog();
}

Then Qt shows me an Assertion Failed:

Widgets must be created in the main thread

Can I get around this issue?

Answer 1

Make the WindowsManager ShowDialog a slot, which it will be invoked from the current thread.

Assuming the WindowsManager has been created, move the WindowsManager class to the main thread: -

windowsManager->moveToThread(QApplication::instance()->thread());

Then invoke the slot with QMetaObject::invoke