So how to choose the files and the paths at the same time

I already said:
@JonB said in How to design a beatiful filedialog object?:

you cannot choose a file here, only a directory/folder

@nicker-player said in How to design a beatiful filedialog object?:

And the dialog looks normally and not ugly.

You read what @jsulm wrote. Why do you not act on it rather than ignoring it?

 QFileDialog* _f_dlg = this;
_f_dlg->setFileMode(QFileDialog::Directory);
 _f_dlg->setOption(QFileDialog::DontUseNativeDialog, true);
QListView *l = _f_dlg->findChild<QListView*>("listView");
if (l) {
        l->setSelectionMode(QAbstractItemView::MultiSelection);
}
QTreeView *t = _f_dlg->findChild<QTreeView*>();
if (t) {
        t->setSelectionMode(QAbstractItemView::MultiSelection);
}

I want to choose the file and the path at the same time

In addition to @jsulm's comment, you cannot choose a file here, only a directory/folder. I would actually expect the dialog to show only directories, not files.

cause I used the setOption function

Why do you set QFileDialog::DontUseNativeDialog?