QObject

[luca72]

Hello i have access through an object in this way:

@
for (int i =0; i<ui->tableWidget->rowCount();i++)
{
QWidget *cbox;
QString nome_combo, nome_classe;
cbox = new QWidget;
cbox = ui->tableWidget->cellWidget(i,4);
nome_combo = cbox->objectName();
nome_classe = cbox->metaObject()->className(); \is qcombobox
nomecl = nome_classe.toStdString();
if (cbox->inherits(nomecl.c_str()))
{
here i need to use the function currentIndex() of the object, but how i can do it?
}
}
@

Thanks

Luca

EDIT: please use @-tags for code highlighting, Gerolf

[Franzk]

@for (int i =0; i<ui->tableWidget->rowCount();i++)
{
QComboBox cbox = qobject_cast<QComboBox>(ui->tableWidget->cellWidget(i,4));
if (cbox)
{
int index = cbox->currentIndex();
}
}@

[giesbert]

Hi luca72,

first of all, you are creating new objects with
@
cbox = new QWidget;
@
and then overwrite the pointer with

@
cbox = ui->tableWidget->cellWidget(i,4);
@

so you create a memory leak. in your if statement, you have to cast.
This is mostly basic C++ knowledge, which is needed to learn Qt.

@
QComboBox* cbobox = qobject_cast<QComboBox*>(cbox);
@

to shorten your code, you could do:

@
for (int i =0; i<ui->tableWidget->rowCount();i++)
{
QWidget cbox = ui->tableWidget->cellWidget(i,4);
if(0 != cbox)
{
QComboBox cbobox = qobject_cast<QComboBox*>(cbox);
if (0 != cbobox)
{
cbobox->currentIndex();
//here i need to use the function currentIndex() of the object, but how i can do it?
}
}
}
@

[Franzk]

Just a remark on Gerolf's suggestion:

[quote author="Gerolf" date="1297092312"]to shorten your code, you could do:
@
for (int i =0; i<ui->tableWidget->rowCount();i++)
{
QWidget cbox = ui->tableWidget->cellWidget(i,4);
if(0 != cbox)
{
QComboBox cbobox = qobject_cast<QComboBox*>(cbox);
if (0 != cbobox)
{
cbobox->currentIndex();
//here i need to use the function currentIndex() of the object, but how i can do it?
}
}
}
@[/quote]

You're checking three times for null here (qobject_cast does it as well). It's not necessary and only clutters your code. The code can be even shorter as I suggested.