How to determine QObject* is empty or not?

[clementNg]

I have tried

if(object != nullptr) {
        qDebug() << "test ";
        qDebug() << QString::fromStdString(event->source()->metaObject()->className());
}

it can enter the checking but I cannot get the className and it crashed on that line. Am I using the wrong method to determine the QObject*? Thank you.

[J.Hilk]

@clementNg
you're checking, if the object is != nullptr, but than you do not use the object but the event.

Shouldn't you rather check if event is valid?

[clementNg]

@J.Hilk
Thank you for your reply.
I dun know how to check the event too. Would you mind to give me some advices?

[J.Hilk]

@clementNg well, what is event ? can you show some more of your code?

[Pl45m4]

@J.Hilk

I think he's referring to this https://forum.qt.io/topic/104192/draggable-itemwidget-in-treewidget/6 and he tries to check if his dropped PushButton is valid or not.

[jsulm]

@clementNg said in How to determine QObject* is empty or not?:

I dun know how to check the event too

If event is a pointer then you do it like you do for object...