Combo Boxes in Item Views/de

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ComboBox in ItemView oder ItemWidget

Beispiel-Code, wie man ComboBoxen als Editor-Widget in einem ItemView oder ItemWidget benutzt

Das Delegate erzeugt eine ComboBox, falls der Index in der zweiten Spalte eines ListView ist. Bei allen anderen Spalten gibt es lediglich den Default-Editor zurück, der von QStyledItemDelegate erzeugt wird.

Datei itemdelegate.h

#ifndef COMBOBOXITEMDELEGATE_H
#define COMBOBOXITEMDELEGATE_H

#include <QStyledItemDelegate>

class ComboBoxItemDelegate : public QStyledItemDelegate
{
    Q_OBJECT
public:
    using QStyledItemDelegate::QStyledItemDelegate;

    QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
    void setEditorData(QWidget *editor, const QModelIndex &index) const override;
    void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const override;
};

#endif // COMBOBOXITEMDELEGATE_H

Datei comboboxitemdelegate.cpp

#include "comboboxitemdelegate.h"
#include <QComboBox>

QWidget *ComboBoxItemDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    // Erzeugen und Füllen der ComboBox
    QComboBox *cb = new QComboBox(parent);
    const int row = index.row();
    cb->addItem(QString("one in row %1").arg(row));
    cb->addItem(QString("two in row %1").arg(row));
    cb->addItem(QString("three in row %1").arg(row));
    return cb;
}


void ComboBoxItemDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
    QComboBox *cb = qobject_cast<QComboBox *>(editor);
    Q_ASSERT(cb);
    // Suche nach dem aktuellen Wert welcher im Model gespeichert ist...
    const QString currentText = index.data(Qt::EditRole).toString();
    const int cbIndex = cb->findText(currentText);
    // ... und setzen der Combobox auf diesen, falls vorhanden.
    if (cbIndex >= 0)
       cb->setCurrentIndex(cbIndex);
}


void ComboBoxItemDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
{
    QComboBox *cb = qobject_cast<QComboBox *>(editor);
    Q_ASSERT(cb);
    model->setData(index, cb->currentText(), Qt::EditRole);
}


Dateimain.cpp

#include <QApplication>
#include <QTableWidget>

#include "comboboxitemdelegate.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QTableWidget tw;

    ComboBoxItemDelegate* cbid = new ComboBoxItemDelegate(&tw);
    // ComboBox only in column 2 
    tw.setItemDelegateForColumn(1, cbid);
    tw.setColumnCount(4);
    tw.setRowCount(10);
    tw.resize(600,400);
    tw.show();

    return a.exec();
}