QT学习之[QTreeWidgetItem]详解，示例

QtreeWidgetItem

树形控件，当选中顶层树形节点时，子节点全部被选中，当取消选择顶层数节点时，子节点全部被取消，当选中子节点时候，父节点显示被选中，示例如下：

用法以及api详解如图：

图片

第一步：

双击UI文件选择，打开ui设计器，拖拽一个Tree Widget 控件，

第二步：

在.h头文件中添加代码：

#include 

在widget声明处添加代码：

public:    Widget(QWidget *parent = nullptr);    ~Widget();    void init();    void updataParentItem(QTreeWidgetItem* item);private slots:    void treeItemChanged(QTreeWidgetItem* item,int column);private:    QTreeWidgetItem* group1;    QTreeWidgetItem* group2;    QTreeWidgetItem* group3;    QTreeWidgetItem* subItem1;    QTreeWidgetItem* subItem2;    QTreeWidgetItem* subItem3;    QTreeWidgetItem* subItem4;    QTreeWidgetItem* subItem5;    QTreeWidgetItem* subItem6;    QTreeWidgetItem* subItem7;    QTreeWidgetItem* subItem8;    QTreeWidgetItem* subItem9;

在widget构造函数添加代码：

 //初始化页面    init();    //发射信号接受相应    connect(ui>treeWidget,SIGNAL(itemChanged(QTreeWidgetItem*,int)),this,SLOT(treeItemChanged(QTreeWidgetItem*,int)));}

init():

void Widget::init(){    ui->treeWidget->clear();    //第一个分组   group1 = new QTreeWidgetItem(ui->treeWidget);   group1->setText(0,"group1");   group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   group1->setCheckState(0,Qt::Unchecked);   subItem1 = new QTreeWidgetItem(group1);   subItem1->setText(0,"subItem1");   subItem1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem1->setCheckState(0,Qt::Unchecked);   subItem2 = new QTreeWidgetItem(group1);   subItem2->setText(0,"subItem2");   subItem2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem2->setCheckState(0,Qt::Unchecked);   subItem3 = new QTreeWidgetItem(group1);   subItem3->setText(0,"subItem3");   subItem3->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem3->setCheckState(0,Qt::Unchecked);   subItem4 = new QTreeWidgetItem(group1);   subItem4->setText(0,"subItem4");   subItem4->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem4->setCheckState(0,Qt::Unchecked);    //分组2   group2 = new QTreeWidgetItem(ui->treeWidget);   group2->setText(0,"group2");   group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   group2->setCheckState(0,Qt::Unchecked);   subItem5 = new QTreeWidgetItem(group2);   subItem5->setText(0,"subItem5");   subItem5->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem5->setCheckState(0,Qt::Unchecked);   subItem6 = new QTreeWidgetItem(group2);   subItem6->setText(0,"subItem6");   subItem6->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem6->setCheckState(0,Qt::Unchecked);   subItem7 = new QTreeWidgetItem(group2);   subItem7->setText(0,"subItem7");   subItem7->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem7->setCheckState(0,Qt::Unchecked);   subItem8 = new QTreeWidgetItem(group2);   subItem8->setText(0,"subItem8");   subItem8->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);   subItem8->setCheckState(0,Qt::Unchecked);}

updataParentItem():

void Widget::updataParentItem(QTreeWidgetItem *item){    QTreeWidgetItem* parent = item->parent();    if(parent == NULL)    {        return;    }    int selectedCount = 0;    int ChildCount = parent->childCount();    for (int i = 0;i < ChildCount; i++) {        QTreeWidgetItem* childItem = parent->child(i);        if(childItem->checkState(0) == Qt::Checked)        {            selectedCount++;        }    }    if(selectedCount <= 0)    {        //未选中        parent->setCheckState(0,Qt::Unchecked);    }    else if(selectedCount > 0 && selectedCount < ChildCount)    {        //部分选中        parent->setCheckState(0,Qt::PartiallyChecked);    }    if(selectedCount == ChildCount)    {        //全选中        parent->setCheckState(0,Qt::Checked);    }}

treeItemChanged（）：

//QTreeWidgetItem自带的信号changitem两个参数，所以这里槽函数也有两个参数void Widget::treeItemChanged(QTreeWidgetItem *item,int column){    QString itemText = item->text(0);    //选中时候未点击    if(Qt::Checked == item->checkState(0))    {        //QTreeWidgetItem* parent = item->parent();        int count = item->childCount();        if(count > 0)        {            for (int i = 0;i < count;i++) {                //子节点选中                item->child(i)->setCheckState(0,Qt::Checked);            }        }        else        {            //是子节点           updataParentItem(item);        }    }    else if (Qt::Unchecked == item->checkState(0))    {        int count = item->childCount();        if(count > 0)        {            for (int i = 0;i < count;i++) {                //子节点选中                item->child(i)->setCheckState(0,Qt::Unchecked);            }        }        else        {           updataParentItem(item);        }    }}

来源地址：https://blog.csdn.net/m0_68197012/article/details/130035626