Les boutons de la barre de navigation UIDocumentPicker sont masqués sous iOS 11

Utiliser CustomDocumentPickerViewController avec du noir appearancepour UINavigationBaretUIBarButtonItem

import UIKit

class CustomDocumentPickerViewController: UIDocumentPickerViewController {

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        UINavigationBar.appearance().tintColor = UIColor.black
        UIBarButtonItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName : UIColor.black], for: .normal)
    }

    override func viewWillDisappear(_ animated: Bool) {

        UINavigationBar.appearance().tintColor = UIColor.white // your color
        UIBarButtonItem.appearance().setTitleTextAttributes(nil, for: .normal)
        super.viewWillDisappear(animated)

    }

}