QTableView中嵌入复选框CheckBox方法:实现QAbstractItemDelegate的paint()函数。

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这种方法和《C++_GUI_Qt4_编程（第二版）》中第十章的自定义委托例子，画星星的作法是一样的，都是通过 QApplication::style()->drawControl(QStyle::CE_CheckBox,&check_box_style_option,painter);这个函数，只不过选择的元素是QCheckBox的。

使用Delegate Paint()函数具体如下:

    void QLineDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option,const QModelIndex& index)const        {            bool checked = index.model()->data(index, Qt::DisplayRole).toBool();                    if(index.column() == 0)            {                QStyleOptionButton check_box_style_option;                check_box_style_option.state |= QStyle::State_Enabled;                if(checked)                {                    check_box_style_option.state |= QStyle::State_On;                }                else                {                    check_box_style_option.state |= QStyle::State_Off;                }                check_box_style_option.rect = CheckBoxRect(option);                QApplication::style()->drawControl(QStyle::CE_CheckBox,&check_box_style_option,painter);            }                    QStyledItemDelegate::paint(painter,option,index);            QStyleOptionViewItem itemOption(option);            if(itemOption.state & QStyle::State_HasFocus)                itemOption.state = itemOption.state ^ QStyle::State_HasFocus;            QStyledItemDelegate::paint(painter,itemOption,index);            QPen oldPen = painter->pen();            painter->setPen(pen);            painter->drawLine(option.rect.topRight(),option.rect.bottomRight());            painter->drawLine(itemOption.rect.bottomLeft(),itemOption.rect.bottomRight());            painter->setPen(oldPen);        }

完整的源代码如下：

    class QLineDelegate : public QStyledItemDelegate      {          Q_OBJECT      public:          QLineDelegate(QTableView* tableView);      protected:          void paint(QPainter* painter,const QStyleOptionViewItem& option,const QModelIndex& index) const;          bool editorEvent(QEvent *event,                                               QAbstractItemModel *model,                                               const QStyleOptionViewItem &option,                                               const QModelIndex &index) ;      private:          QPen         pen;          QTableView*  view;      };            static QRect CheckBoxRect(const QStyleOptionViewItem &view_item_style_options)      {          QStyleOptionButton check_box_style_option;          QRect check_box_rect = QApplication::style()->subElementRect(              QStyle::SE_CheckBoxIndicator,              &check_box_style_option);                QPoint check_box_point(view_item_style_options.rect.x() +                                 view_item_style_options.rect.width() / 2 -                                 check_box_rect.width() / 2,                                 view_item_style_options.rect.y() +                                 view_item_style_options.rect.height() / 2 -                                 check_box_rect.height() / 2);          return QRect(check_box_point, check_box_rect.size());      }                  QLineDelegate::QLineDelegate(QTableView* tableView)      {          int gridHint = tableView->style()->styleHint(QStyle::SH_Table_GridLineColor, new QStyleOptionViewItemV4());          QColor gridColor = static_cast<QRgb>(gridHint);          pen = QPen(gridColor,0,tableView->gridStyle());          view = tableView;      }            void QLineDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option,const QModelIndex& index)const      {          bool checked = index.model()->data(index, Qt::DisplayRole).toBool();                if(index.column() == 0)          {              QStyleOptionButton check_box_style_option;              check_box_style_option.state |= QStyle::State_Enabled;              if(checked)              {                  check_box_style_option.state |= QStyle::State_On;              }              else              {                  check_box_style_option.state |= QStyle::State_Off;              }              check_box_style_option.rect = CheckBoxRect(option);              QApplication::style()->drawControl(QStyle::CE_CheckBox,&check_box_style_option,painter);          }                QStyledItemDelegate::paint(painter,option,index);          QStyleOptionViewItem itemOption(option);          if(itemOption.state & QStyle::State_HasFocus)              itemOption.state = itemOption.state ^ QStyle::State_HasFocus;          QStyledItemDelegate::paint(painter,itemOption,index);          QPen oldPen = painter->pen();          painter->setPen(pen);          painter->drawLine(option.rect.topRight(),option.rect.bottomRight());          painter->drawLine(itemOption.rect.bottomLeft(),itemOption.rect.bottomRight());          painter->setPen(oldPen);      }            bool QLineDelegate::editorEvent(QEvent *event,                                         QAbstractItemModel *model,                                         const QStyleOptionViewItem &option,                                         const QModelIndex &index) {          if((event->type() == QEvent::MouseButtonRelease) ||              (event->type() == QEvent::MouseButtonDblClick))          {              QMouseEvent *mouse_event = static_cast<QMouseEvent*>(event);              if(mouse_event->button() != Qt::LeftButton ||                 !CheckBoxRect(option).contains(mouse_event->pos()))              {                  return false;              }                    if(event->type() == QEvent::MouseButtonDblClick)              {                  return true;              }          }          else if(event->type() == QEvent::KeyPress)          {              if(static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space &&                 static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)              {                  return false;              }          }          else          {              return false;          }                bool checked = index.model()->data(index, Qt::DisplayRole).toBool();          return model->setData(index, !checked, Qt::EditRole);      }

不过有一个小问题，CheckBox旁边有false/true或其它字符的原因是：你的Model中的data返回值，应该排除这列。

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