【接口封装】——18、添加目录项列表响应

 解释：

1、封装内容：列表显示

2、Qt::UserRole：设置不同的值，以此区分多级目录项

函数定义：

	void onTreeItemClicked(QTreeWidgetItem* item);void onTreeItemDoubleClicked(QTreeWidgetItem* item);void onTreeItemExpanded(QTreeWidgetItem* item);void onTreeItemCollapsed(QTreeWidgetItem* item);	//缩放void initContact();

源代码：

void CCMainWindow::initContact()
{//根项QTreeWidgetItem* rootItem = new QTreeWidgetItem;rootItem->setData(0, Qt::UserRole, 0);  //根项设置为 0，子项为 1， 以示区分根项子项RootContactItem* rootWidget = new RootContactItem(true, ui.treeWidget);rootWidget->setText(RootContact_TEXT);ui.treeWidget->addTopLevelItem(rootItem);	//添加顶级项ui.treeWidget->setItemWidget(rootItem, 0, rootWidget);//连接根项目录的信号与槽函数connect(ui.treeWidget, &QTreeWidget::itemClicked, this, &CCMainWindow::onTreeItemClicked);connect(ui.treeWidget, &QTreeWidget::itemDoubleClicked, this, &CCMainWindow::onTreeItemDoubleClicked);connect(ui.treeWidget, &QTreeWidget::itemExpanded, this, &CCMainWindow::onTreeItemExpanded);connect(ui.treeWidget, &QTreeWidget::itemCollapsed, this, &CCMainWindow::onTreeItemCollapsed);		//折叠}void CCMainWindow::onTreeItemClicked(QTreeWidgetItem * item)
{bool isRoot = !(item->data(0, Qt::UserRole).toBool());	//根项被设置为0，isRoot:trueif (isRoot) {item->setExpanded(!item->isExpanded());}}void CCMainWindow::onTreeItemDoubleClicked(QTreeWidgetItem * item)
{bool isChild = item->data(0, Qt::UserRole).toBool();//子项被设置为1if (isChild) {qDebug() << QString::fromLocal8Bit("打开聊天窗口：") << item->data(0, Qt::UserRole + 1);}}void CCMainWindow::onTreeItemExpanded(QTreeWidgetItem * item)
{bool isRoot = !(item->data(0, Qt::UserRole).toBool());	//根项被设置为0，isRoot:trueif (isRoot) {RootContactItem* rootWidget = dynamic_cast<RootContactItem*>(ui.treeWidget->itemWidget(item, 0));if (rootWidget) {rootWidget->setExpanded(true);}}
}//折叠：collapsed
void CCMainWindow::onTreeItemCollapsed(QTreeWidgetItem * item)
{bool isRoot = !(item->data(0, Qt::UserRole).toBool());	//根项被设置为0，isRoot:trueif (isRoot) {//dynamic_cast：强制类型转换RootContactItem* rootWidget = dynamic_cast<RootContactItem*>(ui.treeWidget->itemWidget(item, 0));if (rootWidget) {rootWidget->setExpanded(false);}}}

RootContactItem(bool hasArrow = true, QWidget *parent = nullptr);