QTreeWidget 的用法

Qt QTreeWidget

新建一个Qt Widgets Application，拖拽一个Tree Widget 到 ui 界面上，最后实现的效果如下：

 添加代码

 //test.h

 //在头文件里添加两个公用函数还有一个槽函数的声明

 #include <QTreeWidgetItem>

 public:

  void initTreeWidget();

  void updateParentItem(QTreeWidgetItem *item);

 public:

  void treeItemChanged(QTreeWidgetItem *item,int column);

 //test.cpp

 //在构造函数里添加 connect()

  initTreeWidget();

  connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem *,int)),this,SLOT(treeItemChanged(QTreeWidgetItem*,int)));

 //initTreeWidget() 的实现

 void test::initTreeWidget()

 {

     ui->treeWidget->clear();

     //第一组

     QTreeWidgetItem *group1=new QTreeWidgetItem(ui->treeWidget);

     group1->setText(,"group1");

     group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     group1->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item11=new QTreeWidgetItem(group1);

     item11->setText(,"item11");

     item11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item11->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item12=new QTreeWidgetItem(group1);

     item12->setText(,"item12");

     item12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item12->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item13=new QTreeWidgetItem(group1);

     item13->setText(,"item13");

     item13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item13->setCheckState(,Qt::Unchecked);

     //第二组

     QTreeWidgetItem *group2=new QTreeWidgetItem(ui->treeWidget);

     group2->setText(,"group2");

     group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     group2->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item21=new QTreeWidgetItem(group2);

     item21->setText(,"item21");

     item21->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item21->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item22=new QTreeWidgetItem(group2);

     item22->setText(,"item22");

     item22->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item22->setCheckState(,Qt::Unchecked);

     QTreeWidgetItem *item23=new QTreeWidgetItem(group2);

     item23->setText(,"item23");

     item23->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);

     item23->setCheckState(,Qt::Unchecked);

 }

 //treeItemChanged(QTreeWidgetItem *item, int column)的实现

 void test::treeItemChanged(QTreeWidgetItem *item, int column)

 {

     QString itemText=item->text();

     //选中时

     if(Qt::Checked==item->checkState())

     {

         QTreeWidgetItem* parent=item->parent();

         int count=item->childCount();

         if(count>)

         {

             for(int i=;i<count;i++)

             {

                 //子节点也被选中

                 item->child(i)->setCheckState(,Qt::Checked);

             }

         }

         else

         {

             //是子节点

             updateParentItem(item);

         }

     }

     else if(Qt::Unchecked==item->checkState())

     {

         int count=item->childCount();

         if(count>)

         {

             for(int i=;i<count;i++)

             {

                 item->child(i)->setCheckState(,Qt::Unchecked);

             }

         }

         else

         {

             //是子节点

             updateParentItem(item);

         }

     }

 }

 //updateParentItem(QTreeWidgetItem *item) 的实现

 void test::updateParentItem(QTreeWidgetItem *item)

 {

     QTreeWidgetItem* parent=item->parent();

     if(parent==NULL)

     {

         return;

     }

     //选中的子节点个数

     int selectCount=;

     int childCount=parent->childCount();

     for(int i=;i<childCount;i++)

     {

         QTreeWidgetItem *childItem=parent->child(i);

         if(childItem->checkState()==Qt::Checked)

         {

             selectCount++;

         }

     }

     if(selectCount<=)

     {

         //选中状态

         parent->setCheckState(,Qt::Unchecked);

     }

     else if(selectCount> && selectCount<childCount)

     {

         //部分选中状态

         parent->setCheckState(,Qt::PartiallyChecked);

     }

     else if(selectCount==childCount)

     {

         //未选中状态

         parent->setCheckState(,Qt::Checked);

     }

 }