Failed to get `QModelIndex` for `QFileSystemModel`

[jronald]

#include "MainWindow.h"

#include <QApplication>
#include <QSplitter>
#include <QFileSystemModel>
#include <QTreeView>
#include <QListView>
#include <QMessageBox>

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

    QSplitter *splitter = new QSplitter;

    QFileSystemModel *model = new QFileSystemModel(splitter);
    model->setRootPath(QDir::currentPath());

    QTreeView *tree = new QTreeView(splitter);
    tree->setModel(model);
    tree->setRootIndex(model->index(QDir::currentPath()));

    QListView *list = new QListView(splitter);
    list->setModel(model);
    QModelIndex list_root_index = model->index(QDir::currentPath());
    list->setRootIndex(list_root_index);


    QItemSelectionModel * list_selection_model = list->selectionModel();

    splitter->setWindowTitle("Two views onto the same file system model");
    splitter->show();

    QModelIndex index = model->index(0, 0, list_root_index);
    bool ok = index.isValid();
    assert(ok);
    list_selection_model->select(index, QItemSelectionModel::Select | QItemSelectionModel::Rows);

    return app.exec();
}

assert failed

[SGaist]

Hi,

Take one thing into account, QFileSystemModel is a threaded model so you might be trying to access it while it's not yet populated.

[eyllanesc]

@jronald related https://stackoverflow.com/questions/58759075/why-my-qfilesystemmodel-qmodelindex-couldnt-get-child-node-infomation/58759339#58759339, use directoryLoaded signal.

[jronald]

@SGaist said in Failed to get `QModelIndex` for `QFileSystemModel`:

QFileSystemModel is a threaded model so you might be trying to access it while it's not yet populated.

Tested, it is just the cause of the problem, thanks.

@eyllanesc said in Failed to get `QModelIndex` for `QFileSystemModel`:

use directoryLoaded signal.

It's what's in need, thanks.