QListWidget上面显示图标有关问题

void prepare::list_item(){    QString the_dir(QString(GEN_DIR)+"ico/");    qDebug()<<the_dir;    QDir dir( the_dir, "*.png" );    for ( uint i = 0; i < dir.count(); i++ )    {        QListWidgetItem *listItem =  new QListWidgetItem(QIcon(the_dir+dir[i]), dir[i], listWidget, 0);        qDebug()<<dir[i];        listWidget->setCurrentItem(listItem);    }    listWidget->setFlow(QListView::LeftToRight);    listWidget->update();}