问QFileSystemModel和代理在QTreeView中的排序不同

EN

#include <QtWidgets>
#include <QDebug>

QStringList mountedDrives;

class FSFilter : public QSortFilterProxyModel
{
public:
    FSFilter(QObject *parent)  : QSortFilterProxyModel(parent) {}
protected:
    bool filterAcceptsRow(int row, const QModelIndex &par) const override
    {
        QModelIndex idx = sourceModel()->index(row, 0, par);
        QString path = idx.data(QFileSystemModel::FilePathRole).toString();
        QString path2 = idx.data(Qt::DisplayRole).toString();
        bool mounted = mountedDrives.contains(path);
        if (mounted) {
            qDebug() << "QFileSystemModel::FilePathRole =" << path
                     << "  Qt::DisplayRole =" << path2;
            return true;
        }
        else return false;
    }
};

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    // get mounted drives only
    foreach (const QStorageInfo &storage, QStorageInfo::mountedVolumes()) {
        if (storage.isValid() && storage.isReady()) {
            if (!storage.isReadOnly()) {
                mountedDrives << storage.rootPath();
            }
        }
    }

    QFileSystemModel *fsModel = new QFileSystemModel;
    fsModel->setRootPath("");

    FSFilter *fsFilter = new FSFilter(fsModel);
    fsFilter->setSourceModel(fsModel);
    fsFilter->setSortRole(QFileSystemModel::FilePathRole); // now it works
    fsModel->fetchMore(fsModel->index(0,0));

    QTreeView tree;
    tree.setModel(fsFilter);  // different sort if use  
    tree.setModel(fsFilter);
    tree.setSortingEnabled(true);
    tree.sortByColumn(0, Qt::AscendingOrder);

    tree.resize(800, 400);
    tree.setColumnWidth(0, 300);
    tree.setWindowTitle(QObject::tr("File System Test"));
    tree.show();

    return app.exec();
}

tree.setModel(fsModel);  // use QFileSystemModel, not QSortFilterProxyModel

fsFilter->setFilterRole(QFileSystemModel::FilePathRole);

fsFilter->setSortRole(QFileSystemModel::FilePathRole);