QT QTreeWidget的使用

程序

首先从工具栏拉入一个TreeWidget.

//.h
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTreeWidgetItem>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();
    void init();
    void updateParentItem(QTreeWidgetItem* item);
public slots:
    void treeItemChanged(QTreeWidgetItem* item, int column);


private:
    Ui::Widget *ui;
};

#endif // WIDGET_H

//.cpp
#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    init();
    connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem*,int)),
            this,SLOT(treeItemChanged(QTreeWidgetItem*, int )));//连接槽函数节点改变
}

Widget::~Widget()
{
    delete ui;
}

void Widget::init()
{
    ui->treeWidget->clear();
    QTreeWidgetItem *group1 =new QTreeWidgetItem(ui->treeWidget);
    group1->setText(0,"group1");
    group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);//用户可选、可以使用、可查
    group1->setCheckState(0,Qt::Unchecked);//未选中状态
    QTreeWidgetItem *subItem11 =new QTreeWidgetItem(group1);
    subItem11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem11->setText(0,"subItem11");
    subItem11->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem12 =new QTreeWidgetItem(group1);
    subItem12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem12->setText(0,"subItem12");
    subItem12->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem13 =new QTreeWidgetItem(group1);
    subItem13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem13->setText(0,"subItem13");
    subItem13->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem14 =new QTreeWidgetItem(group1);
    subItem14->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem14->setText(0,"subItem14");
    subItem14->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *group2 =new QTreeWidgetItem(ui->treeWidget);
    group2->setText(0,"group2");
    group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    group2->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem21 =new QTreeWidgetItem(group2);
    subItem21->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem21->setText(0,"subItem21");
    subItem21->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem22 =new QTreeWidgetItem(group2);
    subItem22->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem22->setText(0,"subItem22");
    subItem22->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem23 =new QTreeWidgetItem(group2);
    subItem23->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem23->setText(0,"subItem23");
    subItem23->setCheckState(0,Qt::Unchecked);
    QTreeWidgetItem *subItem24 =new QTreeWidgetItem(group2);
    subItem24->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
    subItem24->setText(0,"subItem24");
    subItem24->setCheckState(0,Qt::Unchecked);




}


void Widget::treeItemChanged(QTreeWidgetItem *item, int column)
{
    if(Qt::Checked == item->checkState(0))//父节点被选中，子节点全选
    {
        int count = item->childCount();
        if(count>0)
        {
            for(int i=0;i<count;i++)
            {
                item->child(i)->setCheckState(0,Qt::Checked);
            }
        }
        else
        {
            updateParentItem(item);//改变父节点
        }
    }
    else if(Qt::Unchecked==item->checkState(0))//父节点取消选中，子节点全部取消选中
    {
        int count = item->childCount();
        if(count>0)
        {
            for(int i=0;i<count;i++)
            {
                item->child(i)->setCheckState(0,Qt::Unchecked);
            }
        }
        else
        {
            updateParentItem(item);
        }
    }
}
void Widget::updateParentItem(QTreeWidgetItem *item)
{
    QTreeWidgetItem* parent=item->parent();//获得父节点
    if(parent==NULL)
    {
        return;
    }
    int selectedCount=0;
    int childCount = parent->childCount();
    for(int i=0;i<childCount;i++)//检查子节点是否被全部选中
    {
        QTreeWidgetItem*childItem=parent->child(i);
        if(childItem->checkState(0)==Qt::Checked)
        {
            selectedCount++;
        }
    }
    if(selectedCount<=0)
    {
        parent->setCheckState(0,Qt::Unchecked);//父节点未选中
    }
    else if(selectedCount>0 && selectedCount<childCount)
    {
        parent->setCheckState(0,Qt::PartiallyChecked);//父节点部分选中
    }
    else if(selectedCount==childCount)
    {
        parent->setCheckState(0,Qt::Checked);//父节点选中
    }

}

效果展示