qcombobox do not display current text when choose item - qt

Question

I have a QComboBox connect to model and display list of text item from model, but when I choose one of its item, QComboBox display item text, but when I click on other widget (QComboBox lost focus), current text become empty
cboProfiles->setModel(QComboBoxModel);
cboProfiles->setModelColumn(0);
cboProfiles->setEditable(true);
follow is my model QComboBoxModel.h
#ifndef QCOMBOBOXMODEL_H
#define QCOMBOBOXMODEL_H
#include <QModelIndex>
class QComboBoxModel : public QAbstractListModel
{
public:
QComboBoxModel(QObject *parent=nullptr);
int rowCount(const QModelIndex &) const;
QVariant data(const QModelIndex &index, int role) const;
void populate(const QList<QPair<int,QString>> &values);
void append(int index, QString value);
private:
QList<QPair<int,QString>> values;
};
#endif // QCOMBOBOXMODEL_H
here is QComboBoxModel.cpp
#include "qcomboboxmodel.h"
#include <QModelIndex>
QComboBoxModel::QComboBoxModel(QObject *parent)
:QAbstractListModel(parent)
{
}
int QComboBoxModel::rowCount(const QModelIndex &) const
{
return values.count();
}
QVariant QComboBoxModel::data( const QModelIndex &index, int role ) const
{
QVariant value;
switch ( role )
{
case Qt::DisplayRole: //string
{
value = this->values.value(index.row()).second;
}
break;
case Qt::UserRole: //data
{
value = this->values.value(index.row()).first;
}
break;
default:
break;
}
return value;
}
void QComboBoxModel::populate(const QList<QPair<int,QString>> &values)
{
this->values = values;
}
void QComboBoxModel::append(int index, QString value)
{
int newRow = this->values.count();
this->beginInsertRows(QModelIndex(), newRow, newRow);
values.append(QPair<int, QString>(index, value));
endInsertRows();
}
here is my use code:
QComboBox* combobox = new QComboBox;
QList<QPair<int, QString>> values;
values.append(QPair<int, QString>(-1, "Select item"));
values.append(QPair<int, QString>(10, "item1(0)"));
values.append(QPair<int, QString>(11, "item1(1)"));
values.append(QPair<int, QString>(21, "item1(2)"));
values.append(QPair<int, QString>(32, "item1(3)"));
values.append(QPair<int, QString>(44, "item1(4)"));
QComboBoxModel *model = new QComboBoxModel();
model->populate(values);
combobox->setModel(model);
combobox->setEditable(true);