<![CDATA[QHBoxLayout delete QPushButton]]>Delete QPushButton in QHBoxLayout fail.

QHBoxLayout *hbox = new QHBoxLayout;

void windowAdded(WId wid){
    Dock *dock = new Dock;
    dock->wid = wid;
    QPushButton *pushButton = new QPushButton(icon, NULL);
    pushButton->setUserData(DOCK, dock);
    hbox->addWidget(pushButton);
}

void windowRemoved(WId wid){
    for (int i=0; i<hbox->count();i++) {
        QLayoutItem *LI = hbox->layout()->itemAt((i));
        QPushButton *pushButton = qobject_cast<QPushButton*>(LI->widget());
        Dock *dock = (Dock*)(pushButton->userData(DOCK));
        if (dock->wid == wid) {
            delete LI;
        }
    }
}
]]>https://forum.qt.io/topic/113029/qhboxlayout-delete-qpushbuttonRSS for NodeFri, 17 Apr 2026 05:19:49 GMTSat, 28 Mar 2020 10:44:15 GMT60<![CDATA[Reply to QHBoxLayout delete QPushButton on Tue, 31 Mar 2020 05:20:06 GMT]]>@SimonSchroeder Strange solved by these:
A layout in a big layout. delete cause overlap.
Change to:
A QWidget with the layout in a big layout, delete work fine.

QList<QPushButton *> list_pushButton = widget_app->findChildren<QPushButton *>();    //QWidget
for (int i=0; i<list_pushButton.count(); i++) {
    Dock *dock = (Dock*)(list_pushButton.at(i)->userData(DOCK));
            if (dock->wid == wid) {
                hbox_app->removeWidget(list_pushButton.at(i));    // QHBoxLayout in QWidget
                list_pushButton.at(i)->deleteLater();
            }
}
]]>https://forum.qt.io/post/585707https://forum.qt.io/post/585707Tue, 31 Mar 2020 05:20:06 GMT<![CDATA[Reply to QHBoxLayout delete QPushButton on Mon, 30 Mar 2020 07:32:34 GMT]]>I have to disagree with mrjj. It is true that the layout owns the push button. However, IIRC the push button also knows its parent and will delete itself from it when deleted. So, at least in theory your code should work.

Nevertheless, I am not sure if you correctly use setUserData/userData. I have never encountered it and the reason for this is that it is not part of the public API. So, the best advice is: Don't use it! Quick googling gave me this: https://stackoverflow.com/questions/8260763/about-using-an-undocumented-class-in-qt Their advice is to use QObject::setProperty instead. You are more likely to get help in this forum if you use only documented features.

]]>https://forum.qt.io/post/585492https://forum.qt.io/post/585492Mon, 30 Mar 2020 07:32:34 GMT<![CDATA[Reply to QHBoxLayout delete QPushButton on Sat, 28 Mar 2020 11:00:18 GMT]]>Hi
The layout owns it so
you must use
https://doc.qt.io/qt-5/qlayout.html#takeAt

and delete that. ( will also delete its widget as far as i remembers )

]]>https://forum.qt.io/post/585245https://forum.qt.io/post/585245Sat, 28 Mar 2020 11:00:18 GMT