QTreeView做出复选框功能

 相关资料：

https://blog.csdn.net/xdw_it/article/details/80973144  

mainwindow.cpp

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

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setWindowTitle(QStringLiteral("QTreeView做出复选框功能"));

    m_publicIconMap[QStringLiteral("treeItem_Project")] = QIcon(QStringLiteral(":/new/image/image/Project.png"));
    m_publicIconMap[QStringLiteral("treeItem_folder")] = QIcon(QStringLiteral(":/new/image/image/folder.png"));
    m_publicIconMap[QStringLiteral("treeItem_folder-ansys")] = QIcon(QStringLiteral(":/new/image/image/folder-ansys.png"));
    m_publicIconMap[QStringLiteral("treeItem_group")] = QIcon(QStringLiteral(":/new/image/image/group.png"));
    m_publicIconMap[QStringLiteral("treeItem_channel")] = QIcon(QStringLiteral(":/new/image/image/channel.png"));

    QStandardItemModel* model = new QStandardItemModel(ui->treeView);
    model->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("项目名")<<QStringLiteral("信息"));
    QStandardItem* itemProject = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_Project")],QStringLiteral("项目"));
    model->appendRow(itemProject);
    model->setItem(model->indexFromItem(itemProject).row(),1,new QStandardItem(QStringLiteral("项目信息说明")));
    QStandardItem* itemFolder = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_folder")],QStringLiteral("文件夹1"));
    itemProject->appendRow(itemFolder);
    itemProject->setChild(itemFolder->index().row(),1,new QStandardItem(QStringLiteral("信息说明")));
    itemFolder = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_folder")],QStringLiteral("文件夹2"));
    itemProject->appendRow(itemFolder);
    for(int i=0;i<5;++i)
    {
        QStandardItem* itemgroup = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_group")],QStringLiteral("组%1").arg(i+1));
        itemFolder->appendRow(itemgroup);
        for(int j=0;j<(i+1);++j)
        {
            QStandardItem* itemchannel = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_channel")],QStringLiteral("频道%1").arg(j+1));
            itemgroup->appendRow(itemchannel);
            itemgroup->setChild(itemchannel->index().row(),1,new QStandardItem(QStringLiteral("频道%1信息说明").arg(j+1)));
        }
    }
    itemProject->setChild(itemFolder->index().row(),1,new QStandardItem(QStringLiteral("文件夹2信息说明")));
    itemProject = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_Project")],QStringLiteral("项目2"));
    itemProject->setCheckable(true);
    itemProject->setTristate(true);
    model->appendRow(itemProject);
    for(int i =0;i<3;++i)
    {
        itemFolder = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_folder")],QStringLiteral("项目2文件夹%1").arg(i+1));
        itemFolder->setCheckable(true);
        itemFolder->setTristate(true);
        QStandardItem* itemFolderDes = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_group")],QStringLiteral("文件夹%1组").arg(i+1));
        itemProject->appendRow(itemFolder);
        itemProject->setChild(itemFolder->index().row(),1,itemFolderDes);
        for(int j=0;j<i+1;++j)
        {
            QStandardItem* item = new QStandardItem(m_publicIconMap[QStringLiteral("treeItem_dataItem")],QStringLiteral("项目%1").arg(j+1));
            item->setCheckable(true);
            itemFolder->appendRow(item);
        }
    }
    //关联项目属性改变的信号和槽
    connect(model,&QStandardItemModel::itemChanged,this,&::MainWindow::on_treeItemChanged);
    //connect(model,SIGNAL(itemChanged(QStandardItem*)),this,SLOT(treeItemChanged(QStandardItem*)));
    ui->treeView->setModel(model);
}

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

void MainWindow::on_treeView_clicked(const QModelIndex &index)
{
    QString sData;
    QString sDir;
    QString sfilePath;
    QString stype;
    QString sfileName;
    QString sFromatStr = QStringLiteral("data:%1 
isDir:%2 
filePath:%3 
type:%4 
fileName:%5");
    sData = index.data().toString();
//    sDir = QString::number(m_pFileModel->isDir(index));
//    sfilePath = m_pFileModel->filePath(index);
//    stype = m_pFileModel->type(index);
//    sfileName = m_pFileModel->fileName(index);

    ui->textEdit->setText("");
    ui->textEdit->append(sFromatStr.arg(sData).arg(sDir).arg(sfilePath).arg(stype).arg(sfileName));
}

// brief 测量兄弟节点的情况，如果都选中返回Qt::Checked，都不选中Qt::Unchecked,不完全选中返回Qt::PartiallyChecked
// param item
// return 如果都选中返回Qt::Checked，都不选中Qt::Unchecked,不完全选中返回Qt::PartiallyChecked
Qt::CheckState MainWindow::checkSibling(QStandardItem * item)
{
    //先通过父节点获取兄弟节点
    QStandardItem * parent = item->parent();
    if(nullptr == parent)
        return item->checkState();
    int brotherCount = parent->rowCount();
    int checkedCount(0),unCheckedCount(0);
    Qt::CheckState state;
    for(int i=0;i<brotherCount;++i)
    {
        QStandardItem* siblingItem = parent->child(i);
        state = siblingItem->checkState();
        if(Qt::PartiallyChecked == state)
            return Qt::PartiallyChecked;
        else if(Qt::Unchecked == state)
            ++unCheckedCount;
        else
            ++checkedCount;
        if(checkedCount>0 && unCheckedCount>0)
            return Qt::PartiallyChecked;
    }
    if(unCheckedCount>0)
        return Qt::Unchecked;
    return Qt::Checked;
}

void MainWindow::on_treeItemChanged(QStandardItem * item)
{
    qDebug() << "on_treeItemChanged";

    if ( item == nullptr )
        return ;
        if ( item->isCheckable ())
        {
            //如果条目是存在复选框的，那么就进行下面的操作
            Qt::CheckState state = item->checkState(); //获取当前的选择状态
            if (item->isTristate())
            {
                 //如果条目是三态的，说明可以对子目录进行全选和全不选的设置
                if ( state != Qt::PartiallyChecked )
                {
                    //当前是选中状态，需要对其子项目进行全选
                    treeItem_checkAllChild ( item , state == Qt::Checked ? true : false );
                }
            }
            else
            {
                //说明是两态的，两态会对父级的三态有影响
                //判断兄弟节点的情况
                treeItem_CheckChildChanged(item);
            }
        }
}

// brief 根据子节点的改变，更改父节点的选择情况
// param item
void MainWindow::treeItem_CheckChildChanged(QStandardItem * item)
{
    if(nullptr == item)
        return;
    Qt::CheckState siblingState = checkSibling(item);
    QStandardItem * parentItem = item->parent();
    if(nullptr == parentItem)
        return;
    if(Qt::PartiallyChecked == siblingState)
    {
        if(parentItem->isCheckable() && parentItem->isTristate())
            parentItem->setCheckState(Qt::PartiallyChecked);
    }
    else if(Qt::Checked == siblingState)
    {
        if(parentItem->isCheckable())
            parentItem->setCheckState(Qt::Checked);
    }
    else
    {
        if(parentItem->isCheckable())
            parentItem->setCheckState(Qt::Unchecked);
    }
    treeItem_CheckChildChanged(parentItem);
}

// brief 递归设置所有的子项目为全选或全不选状态
// param item 当前项目
// param check true时为全选，false时全不选
void MainWindow::treeItem_checkAllChild(QStandardItem *item, bool check)
{
    if(item == nullptr)
        return;
    int rowCount = item->rowCount();
    for(int i=0;i<rowCount;++i)
    {
        QStandardItem* childItems = item->child(i);
        treeItem_checkAllChild_recursion(childItems,check);
    }
    if(item->isCheckable())
        item->setCheckState(check ? Qt::Checked : Qt::Unchecked);
}

void MainWindow::treeItem_checkAllChild_recursion(QStandardItem * item,bool check)
{
    if(item == nullptr)
        return;
    int rowCount = item->rowCount();
    for(int i=0;i<rowCount;++i)
    {
        QStandardItem* childItems = item->child(i);
        treeItem_checkAllChild_recursion(childItems,check);
    }
    if(item->isCheckable())
        item->setCheckState(check ? Qt::Checked : Qt::Unchecked);
}