Qt QListWidgetItem return the checkbox value

Question

screen capture for cannot return the checkstate of the items

I have difficulties to get the state of the checkbox. The code below that can create a clickable checkbox for me. However, I cannot read back the State of the checkbox.

void Admin_view::eq_filter_list_init()
{
 no_of_col_eq=eq_db_list.size();
 for(int i=0;i<no_of_col_eq;i++)
 {
     if(!eq_header_init)
     {
        std::string str = eq_db_list.value(i).toStdString();
        QString eq_header=QString::fromStdString(str);
       QListWidgetItem *item1 = new QListWidgetItem;
       QCheckBox *check = new QCheckBox(eq_header, ui->eq_filter_list);
       check->setCheckState(Qt::Checked);
         //check->show();
       ui->eq_filter_list->addItem(item1);
       ui->eq_filter_list->setItemWidget(item1, check);
       //ui->eq_filter_list->item(i)->setCheckState(Qt::Checked);
     }
     qDebug()<<i<<" check result:"<<item1->checkState();
     qDebug()<<i<<" check result:"<<ui->eq_filter_list->item(i)->checkState();
     }
  }
}

To simplify the testing, I tried to printout the checkstate after I add the items. However even in line12 I have set all checkbox to checked and run the code. All the checkbox are checked, but the checkState in line 18 and 19 are also show Unchecked. And then when I uncheck some of checkbox, I also cannot read the correct checkState.