正如您所说,您可以将组合框作为委托类的成员,并在 createEditor 中创建组合框时将组合框的 currentIndexChanged 信号连接到某个插槽。您应该将组合框声明为可变的,以便在恒定的 createEditor 中对其进行更新。如果一个数据成员被声明为可变的,那么从一个 const 成员函数给这个数据成员赋值是合法的:
#include <QItemDelegate>
#include <QComboBox>
class ComboBoxDelegate: public QItemDelegate
{
Q_OBJECT
public:
ComboBoxDelegate(QObject *parent = 0);
QWidget *createEditor( QWidget *parent,
const QStyleOptionViewItem &option,
const QModelIndex &index ) const;
void setEditorData( QWidget *editor,
const QModelIndex &index ) const;
void setModelData( QWidget *editor,
QAbstractItemModel *model,
const QModelIndex &index ) const;
void updateEditorGeometry( QWidget *editor,
const QStyleOptionViewItem &option,
const QModelIndex &index ) const;
QStringList comboItems;
mutable QComboBox *combo;
private slots:
void setData(int val);
};
ComboBoxDelegate::ComboBoxDelegate(QObject *parent ):QItemDelegate(parent)
{
comboItems<<"Item 1"<<"Item 2"<<"Item 3";
}
QWidget *ComboBoxDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
combo = new QComboBox( parent );
QObject::connect(combo,SIGNAL(currentIndexChanged(int)),this,SLOT(setData(int)));
combo->addItems(comboItems);
combo->setMaxVisibleItems(comboItems.count());
return combo;
}
void ComboBoxDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
QString text = index.model()->data( index, Qt::DisplayRole ).toString();
int comboIndex = comboItems.indexOf(QRegExp(text));
if(comboIndex>=0)
(static_cast<QComboBox*>( editor ))->setCurrentIndex(comboIndex);
}
void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
{
model->setData( index, static_cast<QComboBox*>( editor )->currentText() );
}
void ComboBoxDelegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
editor->setGeometry( option.rect );
}
void ComboBoxDelegate::setData(int val)
{
emit commitData(combo);
//emit closeEditor(combo);
}
在这里,我将组合框的 currentIndexChanged 信号连接到 setData 插槽,该插槽将数据提交给模型。您还可以将该信号连接到您想要的任何插槽。