如何将 UIDocumentPickerViewController 与 UINavigationController 一起使用？

Question

I'm trying to push a UIDocumentPickerViewController onto a UINavigationController's stack However, this results in what looks like two navigation bars. The top bar is the normal navigation bar of the navigation controller. Beneath that is the bar containing the document picker's Cancel and Done buttons. Clicking on the Cancel or Done buttons dismisses the entire view.

Question: How can I properly include a UIDocumentPickerViewController onto a navigation controller's stack, so that the Cancel and Done buttons appear in the navigation bar, and cause the previous and next view controllers to appear?

Answer 1

I believe you should be presenting the UIDocumentPickerViewController controller instead of pushing it onto the stack? I believe it's supposed to be presented because it comes with its own toolbar.

Is there a specific reason it needs to be pushed?

func presentPicker() {

    var documentPicker: UIDocumentPickerViewController = UIDocumentPickerViewController(documentTypes: ["public.text"], inMode: UIDocumentPickerMode.Import)
    documentPicker.delegate = self
    documentPicker.modalPresentationStyle = UIModalPresentationStyle.FullScreen
    self.presentViewController(documentPicker, animated: true, completion: nil)

}

extension viewController: UIDocumentPickerDelegate {
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        // handle picked Document
    }

    func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
        // pop view controller
    }

    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentAt url: URL) {
        // handle picked Document
    }
}