#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTreeWidget>
#include <QString>
#include <QLabel>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QTreeWidget HtmdTreeWidget;
    QTreeWidgetItem HtmdTreeWidgetItems [10];
    QLabel HtmdItemCountLabel,HtmdItemCountLabelOfFruit;

};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "./ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    setWindowTitle("QTreeWidget示例 - 何问起");

    HtmdTreeWidget.move(10,20);
    HtmdTreeWidget.resize(200,230);
    HtmdTreeWidget.setParent(this);
    HtmdTreeWidget.setColumnCount(1);// 设置列 数量 为 1
    HtmdTreeWidget.setHeaderHidden(true);//隐藏头部


    HtmdTreeWidgetItems[0].setText(0,"水果");// 设置节点文本，  by 何问起
    HtmdTreeWidget.addTopLevelItem(&HtmdTreeWidgetItems[0]);//添加顶级节点

    HtmdTreeWidgetItems[1].setText(0,"苹果");
    HtmdTreeWidgetItems[0].addChild(&HtmdTreeWidgetItems[1]);//添加子节点

    HtmdTreeWidgetItems[2].setText(0,"红富士");
    HtmdTreeWidgetItems[1].addChild(&HtmdTreeWidgetItems[2]);

    HtmdTreeWidgetItems[3].setText(0,"黄元帅");
    HtmdTreeWidgetItems[1].addChild(&HtmdTreeWidgetItems[3]);

    HtmdTreeWidgetItems[4].setText(0,"花牛");
    HtmdTreeWidgetItems[1].addChild(&HtmdTreeWidgetItems[4]);

    HtmdTreeWidgetItems[5].setText(0,"葡萄");
    HtmdTreeWidgetItems[0].addChild(&HtmdTreeWidgetItems[5]);

    HtmdTreeWidgetItems[6].setText(0,"黑葡萄");
    HtmdTreeWidgetItems[5].addChild(&HtmdTreeWidgetItems[6]);

    HtmdTreeWidgetItems[7].setText(0,"青葡萄");
    HtmdTreeWidgetItems[5].addChild(&HtmdTreeWidgetItems[7]);

    HtmdTreeWidgetItems[8].setText(0,"蔬菜");
    HtmdTreeWidget.addTopLevelItem(&HtmdTreeWidgetItems[8]);
    //HtmdTreeWidgetItems[8].setSelected(true);//选中该节点，高亮显示

    HtmdTreeWidgetItems[9].setText(0,"白菜");
    HtmdTreeWidgetItems[8].addChild(&HtmdTreeWidgetItems[9]);


   int m_count=0;
   //遍历节点，统计节点数
    QTreeWidgetItemIterator it(&HtmdTreeWidget);
        while (*it) {
            m_count++;
           if((*it)->text(0)=="花牛")
           {
             (*it)->setCheckState(0,Qt::Checked);
           }
            ++it;
        }

        HtmdItemCountLabel.setParent(this);
        HtmdItemCountLabel.move(220,0);//设置某些值，可能会影响 一些节点无法的展开
        HtmdItemCountLabel.setText("通过遍历计算，一共有 "+QString::number(m_count)+" 个节点");

    int m_topLevelItemCount=HtmdTreeWidget.topLevelItemCount();//顶层节点数量
    for(int nIndex = 0; nIndex != m_topLevelItemCount; nIndex++)
    {
    // 开始遍历顶层节点
          HtmdTreeWidget.topLevelItem(nIndex)->setBackground(0,Qt::Dense7Pattern);//设置背景
    }

    HtmdItemCountLabelOfFruit.setParent(this);
    HtmdItemCountLabelOfFruit.setText("水果节点的直接子节点数："+QString::number(HtmdTreeWidgetItems[0].childCount()));
    HtmdItemCountLabelOfFruit.move(220,50);

}

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