添加的JPanel不显示Java

Question

I've been trying to figure why the gameControlArt(which is a JPanel object) does not appear on the gamePanel which is also a JPanel object.

What I am trying to create: the user sees the mainMenuArt(A JPanel object that has a JLabel containing artwork) adding on to the gamePanel upon running the program. When user presses a key, mainMenuArt gets removed. gameControlArt shows up. User presses a key again, gameControlArt gets removed, canvas object gets added to the gamePanel object.

What winds up happening instead: the mainMenuArt appears on the gamePanel which is good. The problem lies after removing the mainMenuArt, the gameControlArt(which is another JPanel object that has a JLabel object containing artwork) does not get added to the gamePanel(which is a JPanel object). Instead it shows the default gray area when a JPanel object has no components added to it. When the user presses a key, the canvas shows up on the gamePanel.

So to sum what the problem is: the gameControlArt does not show up at all like it is suppose to on the gamePanel.

I try updateUI(), revalidate and repaint() but those method calls do not work for some odd reason.

public class GameWindow extends JFrame implements KeyListener{
gamePanel = (JPanel) getContentPane();

gamePanel.remove(mainMenuArt);
gameControlArt = new GameControlArt();
gamePanel.add(gameControlArt);
GameWindow.getGamePanel().revalidate();
}

public class extends Canvas implements KeyListener
{
GameWindow.getGamePanel().add(this);
GameWindow.getGamePanel().revalidate();
}

Answer 1

try getContentPane.add() instead of add.

I'm not sure if it works in this case or not, since I don't know how you have defined gamePanel class, but I hope it does.