QComboBox MaxVisibleItems overflow

[minsoub]

I tried setting MaxVisibleItems of QComboBox.

I tried coding something like :

QComboBox *combo = new QComboBox;
combo->setModel(queryModel);
combo->view()->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
 
// MaxVisibleItems set
QCompleter *p = new QCompleter(queryModel);
p->setMaxVisibleItems(20);
combo->setCompleter(p);
combo->show();

QComboBox *combo = new QComboBox;
combo->setModel(queryModel);
combo->view()->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);

// MaxVisibleItems set
QCompleter *p = new QCompleter(queryModel);
p->setMaxVisibleItems(20);
combo->setCompleter(p);
combo->show();

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The code execute, then QComboBox Size is overflowed and it's height exceed screen size.
QComboBox item count is 300.

Why don't display so MaxVisibleItem as I'm setting?

What's incorret?

please, Somebody help me.