Add QLayout to QWidget which already has a layout

[mikrocat]

I have a QWidget in my Window "AvailableDataWidget" while runtime I add layouts with groupboxes, labels and checkboxes. I want to delete them later and add new groupboxes and checkboxes.

This is the way I create it:

void MonitorWindow::on_actionGetAvailableData_triggered(){
       QVBoxLayout* verticalLayout[NumberOfAvailableTypes];
       QVBoxLayout* verticalLayoutForWidget = new QVBoxLayout(ui->AvailableDataWidget);
 
       QGroupBox *TypeGroupBox[NumberOfAvailableTypes];
 
        for (int i = 0; i < NumberOfAvailableTypes; i++){           //1 groupbox for each type
            TypeGroupBox[i] = new QGroupBox(ui->AvailableDataWidget);
            TypeGroupBox[i]->setTitle(DataList.at(i).name);
            verticalLayout[i] = new QVBoxLayout(TypeGroupBox[i]);
 
            if (DataList.at(i).type != TYPEBINARY){
                QCheckBox *DataCheckbox[DataList.at(i).quantity];
                QLabel* tempLabel[DataList.at(i).quantity];
                QHBoxLayout* horizontalLayout[DataList.at(i).quantity];
 
                for (int j = 1; j <= DataList.at(i).quantity; j++){  
                    DataCheckbox[j] = new QCheckBox(TypeGroupBox[i]);
                    DataCheckbox[j]->setChecked(false);
                    connect(DataCheckbox[j],SIGNAL(clicked()),SLOT(setTransducerFlags()));
                    horizontalLayout[j] = new QHBoxLayout();
                    horizontalLayout[j]->addWidget(DataCheckbox[j]);
 
                    tempLabel[j] = new QLabel(TypeGroupBox[i]);
                    tempLabel[j]->setText(QString("%1%2%3").arg(DataList.at(i).name).arg(" ").arg(j));
                    horizontalLayout[j]->addWidget(tempLabel[j]);
 
                    verticalLayout[i]->addLayout(horizontalLayout[j]);
                }
            }
            else{
                ...
                QCheckBox *DataCheckbox = new QCheckBox(TypeGroupBox[i]);
                DataCheckbox->setChecked(false);
                connect(DataCheckbox,SIGNAL(clicked()),SLOT(setTransducerFlags()));
                QLabel* tempLabel = new QLabel(TypeGroupBox[i]);
                tempLabel->setText(DataList.at(i).name);
                QHBoxLayout* horizontalLayout = new QHBoxLayout;
                horizontalLayout->addWidget(DataCheckbox);
                horizontalLayout->addWidget(tempLabel);
                myTransducermodel->addColumn(DataList.at(i).name);
                verticalLayout[i]->addLayout(horizontalLayout);
            }
            verticalLayoutForWidget->addWidget(TypeGroupBox[i]);
        }
    }
}

void MonitorWindow::on_actionGetAvailableData_triggered(){
       QVBoxLayout* verticalLayout[NumberOfAvailableTypes];
       QVBoxLayout* verticalLayoutForWidget = new QVBoxLayout(ui->AvailableDataWidget);

       QGroupBox *TypeGroupBox[NumberOfAvailableTypes];

        for (int i = 0; i < NumberOfAvailableTypes; i++){           //1 groupbox for each type
            TypeGroupBox[i] = new QGroupBox(ui->AvailableDataWidget);
            TypeGroupBox[i]->setTitle(DataList.at(i).name);
            verticalLayout[i] = new QVBoxLayout(TypeGroupBox[i]);

            if (DataList.at(i).type != TYPEBINARY){
                QCheckBox *DataCheckbox[DataList.at(i).quantity];
                QLabel* tempLabel[DataList.at(i).quantity];
                QHBoxLayout* horizontalLayout[DataList.at(i).quantity];

                for (int j = 1; j <= DataList.at(i).quantity; j++){  
                    DataCheckbox[j] = new QCheckBox(TypeGroupBox[i]);
                    DataCheckbox[j]->setChecked(false);
                    connect(DataCheckbox[j],SIGNAL(clicked()),SLOT(setTransducerFlags()));
                    horizontalLayout[j] = new QHBoxLayout();
                    horizontalLayout[j]->addWidget(DataCheckbox[j]);

                    tempLabel[j] = new QLabel(TypeGroupBox[i]);
                    tempLabel[j]->setText(QString("%1%2%3").arg(DataList.at(i).name).arg(" ").arg(j));
                    horizontalLayout[j]->addWidget(tempLabel[j]);

                    verticalLayout[i]->addLayout(horizontalLayout[j]);
                }
            }
            else{
                ...
                QCheckBox *DataCheckbox = new QCheckBox(TypeGroupBox[i]);
                DataCheckbox->setChecked(false);
                connect(DataCheckbox,SIGNAL(clicked()),SLOT(setTransducerFlags()));
                QLabel* tempLabel = new QLabel(TypeGroupBox[i]);
                tempLabel->setText(DataList.at(i).name);
                QHBoxLayout* horizontalLayout = new QHBoxLayout;
                horizontalLayout->addWidget(DataCheckbox);
                horizontalLayout->addWidget(tempLabel);
                myTransducermodel->addColumn(DataList.at(i).name);
                verticalLayout[i]->addLayout(horizontalLayout);
            }
            verticalLayoutForWidget->addWidget(TypeGroupBox[i]);
        }
    }
}

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So I need to delete the layout and widgets, right?
AvailableDataWidget should be the parent of all layouts and widgets, so i tried this:

QList<QWidget *> widgets = ui->AvailableDataWidget->findChildren<QWidget *>();
   foreach(QWidget * widget, widgets){
       delete widget;
    }

QList<QWidget *> widgets = ui->AvailableDataWidget->findChildren<QWidget *>();
   foreach(QWidget * widget, widgets){
       delete widget;
    }

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but it makes my program crash.

[anda_skoa]

AvailableDataWidget should be the parent of all layouts and widgets, so i tried this:

QList<QWidget *> widgets = ui->AvailableDataWidget->findChildren<QWidget *>();
   foreach(QWidget * widget, widgets){
       delete widget;
    }

QList<QWidget *> widgets = ui->AvailableDataWidget->findChildren<QWidget *>();
   foreach(QWidget * widget, widgets){
       delete widget;
    }

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but it makes my program crash.

QObject::findChildren() is recursive by default, so you get the immediate children and their children and so on.
When you delete a QObject object, it will delete all its children, so some of the pointers in your list will already have become invalid.

Cheers,
_