在UINav栏中没有显示Swift后退按钮

Question

我的Swift代码中有这个简单的代码

let PostPage = PostView()
navigationController?.pushViewController(PostPage, animated: true)

class PostView: UIViewController 

此代码执行它应该执行的操作，即显示PostView，但是当显示此视图时，我希望UINavbar的标题将被更改，并且将显示后退按钮。但这些都不会发生

AppDelegate中的

window?.rootViewController = UINavigationController(rootViewController: TabNavigator())

Answer 1

好像你正在将rootViewController从NavigationController更改为ViewController。

HBox root = new HBox();
    ArrayList<String> items = new ArrayList<String>();
        String textLine;
    Button btn = null;
        try
    {
      InputStream inputStream = JavaFX_Paths.class.getResourceAsStream("/imagens/lista_imagens.txt");
      InputStreamReader inputReader = new InputStreamReader(inputStream);
            BufferedReader bufferReader = new BufferedReader(inputReader);
            while ((textLine = bufferReader.readLine()) != null)
                items.add(textLine);
            bufferReader.close();
      inputReader.close();
      inputStream.close();
    }
    catch (IOException ex)
    {
      Logger.getLogger(JavaFX_Paths.class.getName()).log(Level.SEVERE, null, ex);
    }
    for (int i = 0; i < items.size(); i++)
    {
      Image img = new Image(getClass().getResourceAsStream("/imagens/" + items.get(i) + ".png"));
      btn = new Button();
      btn.setId(items.get(i));
      btn.setGraphic(new ImageView(img));
      root.getChildren().addAll(btn);
    }

因此rootViewController不再是navigationController。