如何将返回的 ArrayList 中的 TextArea 添加到框架中？

Question

I am trying to return an ArrayList with two values, text and a text area. However when I press the button that is meant to do this, nothing happens. Can you please explain why this is the case?

The method that returns the ArrayList:

public ArrayList<Object> newFile(){
      ArrayList<Object> objectArrayList = new ArrayList<>();
      TextArea textField = new TextArea("Type File Information.., ");
      AtomicReference<String> fileText = new AtomicReference<>();


      textField.addTextListener((textListener) -> {
          fileText.set(textField.getText());
      });
      objectArrayList.add(String.valueOf(fileText));
      objectArrayList.add(textField);

      return objectArrayList;
    }
}

The code snippet that executes the method and gets the text area:

public void actionPerformed(ActionEvent e) {
        String action = e.getActionCommand();

        switch (action) {
            case "New":
                fileText = (String) newFile().get(0);
                MainMenu mainMenu = new MainMenu();
                mainMenu.add((TextArea)newFile().get(1));
                break;

The code snippet where I add the handler:

newFile.addActionListener(mainMenuHandler);

Answer 1

Why are you using AWT. You should at least be using Swing.

MainMenu mainMenu = new MainMenu();
mainMenu.add((TextArea)newFile().get(1));

In your case you add the text area to the MainMenu, but you never add the MainMenu to the frame.

So you would need to add the "mainMenu" to the frame.

Also, when using Swing if you add a component to a visible frame then you need to invoke revalidate() and repaint() on the container you add the component to.