Qt之QTableView添加复选框（QAbstractItemDelegate）

简述

上节分享了使用自定义模型QAbstractTableModel来实现复选框。下面我们来介绍另外一种方式：
自定义委托-QAbstractItemDelegate。

效果

QAbstractTableModel

源码

table_model.cpp

#define CHECK_BOX_COLUMN 0#define File_PATH_COLUMN 1TableModel::TableModel(QObject *parent)    : QAbstractTableModel(parent){}TableModel::~TableModel(){}// 更新表格数据void TableModel::updateData(QList<FileRecord> recordList){    m_recordList = recordList;    beginResetModel();    endResetModel();}// 行数int TableModel::rowCount(const QModelIndex &parent) const{    return m_recordList.count();}// 列数int TableModel::columnCount(const QModelIndex &parent) const{    return 2;}// 设置表格项数据bool TableModel::setData(const QModelIndex &index, const QVariant &value, int role){    if (!index.isValid())        return false;    int nColumn = index.column();    FileRecord record = m_recordList.at(index.row());    switch (role)    {    case Qt::DisplayRole:    {        if (nColumn == File_PATH_COLUMN)        {            record.strFilePath = value.toString();            m_recordList.replace(index.row(), record);            emit dataChanged(index, index);            return true;        }    }    case Qt::CheckStateRole:    case Qt::UserRole:    {        if (nColumn == CHECK_BOX_COLUMN)        {            record.bChecked = value.toBool();            m_recordList.replace(index.row(), record);            emit dataChanged(index, index);            return true;        }    }    default:        return false;    }    return false;}// 表格项数据QVariant TableModel::data(const QModelIndex &index, int role) const{    if (!index.isValid())        return QVariant();    int nRow = index.row();    int nColumn = index.column();    FileRecord record = m_recordList.at(nRow);    switch (role)    {    case Qt::TextColorRole:        return QColor(Qt::white);    case Qt::TextAlignmentRole:        return QVariant(Qt::AlignLeft | Qt::AlignVCenter);    case Qt::DisplayRole:    {        if (nColumn == File_PATH_COLUMN)            return record.strFilePath;        return "";    }    case Qt::UserRole:    {        if (nColumn == CHECK_BOX_COLUMN)            return record.bChecked;    }    default:        return QVariant();    }    return QVariant();}// 表头数据QVariant TableModel::headerData(int section, Qt::Orientation orientation, int role) const{    switch (role)    {    case Qt::TextAlignmentRole:        return QVariant(Qt::AlignLeft | Qt::AlignVCenter);    case Qt::DisplayRole:    {        if (orientation == Qt::Horizontal)        {            if (section == CHECK_BOX_COLUMN)                return QStringLiteral("状态");            if (section == File_PATH_COLUMN)                return QStringLiteral("文件路径");        }    }    default:        return QVariant();    }    return QVariant();}// 表格可选中、可复选Qt::ItemFlags TableModel::flags(const QModelIndex &index) const{    if (!index.isValid())        return QAbstractItemModel::flags(index);    Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;    return flags;}

接口说明

• updateData
  主要用于更新数据，刷新界面。

• data
  用来显示数据，根据角色（颜色、文本、对齐方式、选中状态等）判断需要显示的内容。

• setData
  用来设置数据，根据角色（颜色、文本、对齐方式、选中状态等）判断需要设置的内容。

• headerData
  用来显示水平/垂直表头的数据。

• flags
  用来设置单元格的标志（可用、可选中、可复选等）。

QStyledItemDelegate

源码

CheckBoxDelegate::CheckBoxDelegate(QObject *parent)    : QStyledItemDelegate(parent){}CheckBoxDelegate::~CheckBoxDelegate(){}// 绘制复选框void CheckBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const{    QStyleOptionViewItem viewOption(option);    initStyleOption(&viewOption, index);    if (option.state.testFlag(QStyle::State_HasFocus))        viewOption.state = viewOption.state ^ QStyle::State_HasFocus;    QStyledItemDelegate::paint(painter, viewOption, index);    if (index.column() == CHECK_BOX_COLUMN)    {        bool data = index.model()->data(index, Qt::UserRole).toBool();        QStyleOptionButton checkBoxStyle;        checkBoxStyle.state = data ? QStyle::State_On : QStyle::State_Off;        checkBoxStyle.state |= QStyle::State_Enabled;        checkBoxStyle.iconSize = QSize(20, 20);        checkBoxStyle.rect = option.rect;        QCheckBox checkBox;        QApplication::style()->drawPrimitive(QStyle::PE_IndicatorCheckBox, &checkBoxStyle, painter, &checkBox);    }}// 响应鼠标事件，更新数据bool CheckBoxDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index){    QRect decorationRect = option.rect;    QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);    if (event->type() == QEvent::MouseButtonPress && decorationRect.contains(mouseEvent->pos()))    {        if (index.column() == CHECK_BOX_COLUMN)        {            bool data = model->data(index, Qt::UserRole).toBool();            model->setData(index, !data, Qt::UserRole);        }    }    return QStyledItemDelegate::editorEvent(event, model, option, index);}

接口说明

• paint
  用来设置表格样式，绘制复选框-状态、大小、显示区域等。

• editorEvent
  用来设置数据，响应鼠标事件，判断当前选中状态，互相切换。

样式

复选框样式：

QCheckBox{        spacing: 5px;        color: white;}QCheckBox::indicator {        width: 17px;        height: 17px;}QCheckBox::indicator:enabled:unchecked {        image: url(:/Images/checkBox);}QCheckBox::indicator:enabled:unchecked:hover {        image: url(:/Images/checkBoxHover);}QCheckBox::indicator:enabled:unchecked:pressed {        image: url(:/Images/checkBoxPressed);}QCheckBox::indicator:enabled:checked {        image: url(:/Images/checkBoxChecked);}QCheckBox::indicator:enabled:checked:hover {        image: url(:/Images/checkBoxCheckedHover);}QCheckBox::indicator:enabled:checked:pressed {        image: url(:/Images/checkBoxCheckedPressed);}QCheckBox::indicator:enabled:indeterminate {        image: url(:/Images/checkBoxIndeterminate);}QCheckBox::indicator:enabled:indeterminate:hover {        image: url(:/Images/checkBoxIndeterminateHover);}QCheckBox::indicator:enabled:indeterminate:pressed {        image: url(:/Images/checkBoxIndeterminatePressed);}

使用

QTableView *pTableView = new QTableView(this);TableModel *pModel = new TableModel(this);CheckBoxDelegate *pDelegate = new CheckBoxDelegate(this);// 设置单行选中、最后一列拉伸、表头不高亮、无边框等pTableView->setSelectionBehavior(QAbstractItemView::SelectRows);pTableView->horizontalHeader()->setStretchLastSection(true);pTableView->horizontalHeader()->setHighlightSections(false);pTableView->verticalHeader()->setVisible(false);pTableView->setShowGrid(false);pTableView->setFrameShape(QFrame::NoFrame);pTableView->setSelectionMode(QAbstractItemView::SingleSelection);pTableView->setModel(pModel);pTableView->setItemDelegate(pDelegate);// 加载数据、更新界面QList<FileRecord> recordList;for (int i = 0; i < 5; ++i){    FileRecord record;    record.bChecked = false;    record.strFilePath = QString("E:/Qt/image_%1.png").arg(i + 1);    recordList.append(record);}pModel->updateData(recordList);