Question

我正在尝试从另一个类更新Jlabel的文本。我尝试使用setText方法，这会导致程序编译正常并运行，但是当我按下按钮时没有任何反应。

以下是我的Menu.class中的代码，Jlabel所在的位置。

public class Menu extends JFrame {


    private JPanel contentPane;
    private JLabel lblOthello;

      public static void main(String[] args) {

            EventQueue.invokeLater(new Runnable() {
              public void run() {
                Menu frame = new Menu();
                frame.setVisible(true);
              }
            });

          }

    public Menu() {
        //Sets program icon
        ImageIcon img = new ImageIcon("icon.png");
        //Creates the frame
        setForeground(Color.RED);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 384, 475);
        contentPane = new JPanel();
        contentPane.setBackground(Color.BLACK);
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        lblOthello = new JLabel("Othello");
        lblOthello.setForeground(Color.YELLOW);
        lblOthello.setFont(new Font("Franklin Gothic Medium Cond", Font.BOLD, 33));
        lblOthello.setHorizontalAlignment(SwingConstants.CENTER);
        lblOthello.setBounds(0, 0, 366, 59);

        contentPane.add(lblOthello);


        JButton btnNewButton = new JButton("New Singleplayer Game");
        btnNewButton.setForeground(Color.BLACK);
        btnNewButton.setBackground(UIManager.getColor("Button.background"));
        btnNewButton.setBounds(10, 72, 344, 45);
        btnNewButton.addActionListener(new ButtonListener());
        contentPane.add(btnNewButton);

        JButton btnNewMultiplayerGame = new JButton("New Dualplayer Game");
        btnNewMultiplayerGame.setBounds(10, 130, 344, 45);
        btnNewMultiplayerGame.addActionListener(new ButtonListener());
        contentPane.add(btnNewMultiplayerGame);

        JSeparator separator = new JSeparator();
        separator.setBounds(0, 57, 366, 2);
        contentPane.add(separator);

        JButton btnNewNetworkGame = new JButton("New Network Game");
        btnNewNetworkGame.setBounds(10, 188, 344, 45);
        btnNewNetworkGame.addActionListener(new ButtonListener());
        contentPane.add(btnNewNetworkGame);


        JButton btnAbout = new JButton("AI vs AI Game");
        btnAbout.setBounds(10, 246, 344, 45);
        btnAbout.addActionListener(new ButtonListener());
        contentPane.add(btnAbout);

        JButton btnNewButton_1 = new JButton("QUIT");
        btnNewButton_1.setBounds(10, 446, 344, 25);
        btnNewButton_1.addActionListener(new ButtonListener());
        contentPane.add(btnNewButton_1);

        JLabel lblNewLabel = new JLabel("New label");
        lblNewLabel.setIcon(new ImageIcon("C:\\Users\\User\\workspace\\Othello\\src\\Othello.jpg"));
        lblNewLabel.setBounds(0, -36, 366, 507);
        contentPane.add(lblNewLabel);

        JButton button = new JButton("QUIT");
        button.setBounds(10, 390, 344, 25);
        button.addActionListener(new ButtonListener());
        contentPane.add(button);

        JSeparator separator_1 = new JSeparator();
        separator_1.setBounds(0, 375, 366, 2);
        contentPane.add(separator_1);






    }

    public void setText(String text) {
        lblOthello.setText(text);
          System.out.println("executed");

        contentPane.validate();
        contentPane.repaint();

    }
}

以下是从我的buttonlistener类

执行settext方法的代码部分

    case PLAYER_VS_AI:
        Menu men = new Menu();
        men.setText("Now");
        men.revalidate();
        men.repaint();
        break;

有谁能告诉我为什么这不起作用？

Answer 1

每按一次按钮，您就会创建一个新的Menu对象，而不是修改现有的Menu对象。

从另一个类更新Jlabel文本

1 个答案: