Question

我正在尝试使用文本设置可见标签。但GUI不会更新它。你能看看代码并给我建议吗？我有几个控制器类，下面我介绍了其中两个。操作主屏幕负责检测点击次数，管理日志面板应检查数据是否正确并更新视图。

主：

public class Main {

    public static void main(String[] args) {

        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Model model = new Model();
                    MainScreen window = new MainScreen(model);
                    ActionMainScreen actionMainScreen = new ActionMainScreen(
                            model, window);
                    OpenClose openClose = new OpenClose();

                    actionMainScreen.connectToServer();
                    window.getFrame().setVisible(true); // GUI
                    actionMainScreen.contol(); // GUI controllers

                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

}

控制器（动作主屏幕）：

public class ActionMainScreen {

    private MainScreen viewMain;
    private OpenClose openClose = new OpenClose();
    private ConnectionNetwork connectionNetwork = new ConnectionNetwork();
    private UpdateData updateData = new UpdateData();
    private Model model = new Model();
    private AdminLogPanel admPanel = new AdminLogPanel();

    public ActionMainScreen(Model model, MainScreen window) {
        this.viewMain = window;
    }

    public void connectToServer() {

        try {
            connectionNetwork.connectToServer();

        } catch (UnknownHostException e1) {
            e1.printStackTrace();
        } catch (java.net.ConnectException e1) {
            e1.printStackTrace();
            System.out.println("ConnectException");
        } catch (IOException e1) {
            e1.printStackTrace();
        }

    }

    public void contol() {

        openClose.checkByTheFirstTime();
        updateData.changeText();

        viewMain.getBtnLogIn().addActionListener(new ActionListener() {

            String login;
            String password;

            @Override
            public void actionPerformed(ActionEvent e) {

                login = viewMain.getTextFieldLogin().getText();
                password = new String(viewMain.getPasswordField().getPassword());
                admPanel.checkIfAdmin(login, password);
            }
        });
    }
}

控制器（管理员日志面板）：

public class AdminLogPanel {

    Model model = new Model();
    MainScreen mainScreen = new MainScreen(model);

    public void checkIfAdmin(String login, String password) {

        if (ModelAdmin.getLogin().equals(login)
                && ModelAdmin.getPassword().equals(password)) {
            System.out.println("HURA!");
            mainScreen.getLblLoginOrPassword().setVisible(true);

            JOptionPane.showMessageDialog(null, "OK");



        } else {


            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    System.out.println(SwingUtilities.isEventDispatchThread()); // true
                    mainScreen.getLblLoginOrPassword().setText("abc"); // correct text in console
                    System.out.println(mainScreen.getLblLoginOrPassword().getText());
                    mainScreen.getLblLoginOrPassword().setVisible(true); // nothing happened 


            mainScreen.getLblLoginOrPassword().repaint();
                mainScreen.getPanel_1().repaint();
            }
        });
    }
}

}

查看：

public class MainScreen {

    public MainScreen(Model model) {
        initialize();
    }

    private JButton btnLogIn;
    private JLabel lblLoginOrPassword;
    public JLabel getLblLoginOrPassword() {
        return lblLoginOrPassword;
    }

    public void setLblLoginOrPassword(JLabel lblLoginOrPassword) {
        this.lblLoginOrPassword = lblLoginOrPassword;
    }

    public JButton getBtnLogIn() {
        return btnLogIn;
    }

(....)
lblLoginOrPassword = new JLabel("Login or Password is incorrect!");

        lblLoginOrPassword.setFont(new Font("Tahoma", Font.BOLD, 17));
        lblLoginOrPassword.setVisible(false);

}

Answer 1

您将窗口的可见性设置为true，但是您没有将JLabel的可见性设置为true，您也可以尝试调用pack（）。另一个有用的提示是确保你的组件使用布局，也许像CardLayout。

Answer 2

我道歉，我无法测试你的代码。太大了。但是，您可以在更新代码之后添加以下代码段吗？

SwingUtilities.updateComponentTreeUI(component);

这里“组件”是框架下的顶层。

无法setVisible为true

2 个答案: