Qt中搜索框输入不同字符串显示列表的内容改变

void FixedWingAircraftModelManager::slotBackgroundFilter(QString f){ // 根据lineEdit框内文字，动态刷新item列表显示
    const bool empty = f.isEmpty();
    QRegExp re = empty ? QRegExp() : QRegExp(f,Qt::CaseInsensitive,QRegExp::FixedString);

    const int numTopLevels = ui->treeWidget->topLevelItemCount();
    for(int i = 0; i< numTopLevels; i++ ){
        QTreeWidgetItem *ti = ui->treeWidget->topLevelItem(i);
        setBackgroundFilter(ti,re);
    }
}

int setTreeItemHidden(QTreeWidgetItem* item){
    if(item->childCount() != 0){
        for(int i = 0; i < item->childCount(); i++){
            item->child(i)->setHidden(false);
            setTreeItemHidden(item->child(i));
        }
    }
    return 0;
}

int setBackgroundFilter(QTreeWidgetItem *item,QRegExp re){
    if(item == NULL) return 0;
    int nVisibleCount = 0;
    int count = item->childCount();

    QString text = item->text(0);
    bool bMatched = text.contains(re);
    if(bMatched){
        item->setHidden(false);
        setTreeItemHidden(item);
        return count;
    }else{
        for(int i = 0; i< count; i++){
            QTreeWidgetItem* child = item->child(i);
            setBackgroundFilter(child,re);
            if(!child->isHidden()){
                nVisibleCount ++;
            }
        }
    }
    item->setHidden(nVisibleCount == 0);
    return nVisibleCount;
}