QAbstractItemModel 与 QSortFilterProxyModel 的奇怪交互

Question

这是QAbstractItemModel与QSortFilterProxyModel的交互有什么问题？在屏幕的左侧，我连接了QAbstractItemModel的实现，在右侧，我做了QSortFilterProxyModel。

UPD：上传代码：[e-mail]：h0x0d9/myfilterproxymodel.git

法典：

ListsRegisterModel *model = new ListsRegisterModel(this);
QSortFilterProxyModel *proxyModel = new QSortFilterProxyModel(this);
proxyModel->setSourceModel(model);

QTreeView *view = new QTreeView(this);
view->setModel(model);
QTreeView *view2 = new QTreeView(this);
view2->setModel(proxyModel);

头：

class ListsRegisterModel : public QAbstractItemModel
{
    Q_OBJECT
public:
    explicit ListsRegisterModel(QObject *parent = 0);
    ~ListsRegisterModel();
    QVariant data(const QModelIndex &index, int role) const;
    Qt::ItemFlags flags(const QModelIndex &index) const;
    QVariant headerData(int section, Qt::Orientation orientation,
                        int role = Qt::DisplayRole) const;
    QModelIndex index(int row, int column,
                      const QModelIndex &parent = QModelIndex()) const;
    QModelIndex parent(const QModelIndex &index) const;
    int rowCount(const QModelIndex &parent = QModelIndex()) const;
    int columnCount(const QModelIndex &parent = QModelIndex()) const;
    bool setData(const QModelIndex &index, const QVariant &value,
                 int role = Qt::CheckStateRole);
private:
    enum Columns
    {
        RamificationColumn,
        ListNameColumn = RamificationColumn,
        ListSubscriberColumn
    };
    TreeItem *rootItem;
    QMultiMap<QString, QString> parseListsFile(QString path);
    void setupModelData(QMultiMap<QString, QString> lists, TreeItem *parent);
    TreeItem *getItem(const QModelIndex &index) const;
};

ListsRegisterModel::ListsRegisterModel(QObject *parent) :
    QAbstractItemModel(parent)
{
    QList<QVariant> rootData;
    rootData << tr("List") << tr("Subscribers");
    rootItem = new TreeItem(rootData);
    QMultiMap<QString, QString> listsReg = parseListsFile("etc/lists.reg");
    setupModelData(listsReg, rootItem);
}

QVariant ListsRegisterModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();
    TreeItem *item = getItem(index);
    switch (role) {
    case Qt::DisplayRole:
        if (item->parent() == rootItem) {
            return item->data(index.column());
        }
        else {
            qDebug() << item->data(index.column() - 1);
            return item->data(index.column() - 1);
        }
        break;
    case Qt::CheckStateRole:
        if (index.column() == RamificationColumn
                && item->parent() == rootItem) {
            return QVariant(item->checkState());
        }
        break;
    default:
        return QVariant();
        break;
    }
    return QVariant();
}


QModelIndex ListsRegisterModel::index(int row, int column, const QModelIndex &parent) const
{
    TreeItem * parentItem;
    if (row < 0 || column < 0)
        return QModelIndex();
    if (!parent.isValid())
        parentItem = rootItem;
    else
        parentItem = getItem(parent);
    TreeItem *childItem = parentItem->child(row);
    if (childItem)
        return createIndex(row, column, childItem);
    return QModelIndex();
}

QModelIndex ListsRegisterModel::parent(const QModelIndex &index) const
{
    if (!index.isValid())
        return QModelIndex();
    TreeItem *childItem = getItem(index);
    TreeItem *parentItem = childItem->parent();
    if (parentItem == rootItem)
        return QModelIndex();
    return createIndex(parentItem->row(), 0, parentItem);
}

Answer 1

我把灰烬洒在我的头上。我定义了错误的columnCount（）函数。正确的版本是这样的：

int ListsRegisterModel::columnCount(const QModelIndex &parent) const
{
    return LastColumn; // = 2
}