Question

问题可能不正确，但我不知道如何正确询问。对不起，我很抱歉。

问题在于：

我的JFrame CardLayout为layout manager。我有三个JPanel＆我在它们之间切换。一切都很好，直到我不得不将2 JPanel加入其中一个。现在我的JPanel之一应该包含另外两个JPanel＆＃39}。我在某处读到它是可行的。因此JPanel应该有BorderLayout。它应该如何： enter image description here

以下是我之前的事情：

我的JFrame课程：

public class JavaGame2 extends JFrame {

    public JavaGame2(){

        CardLayout layout = new CardLayout();
        setLayout(layout);
        GameController controller = new CardLayoutGameController(getContentPane(), layout);

        gamePanel = new GamePanel(controller);          
        menuPanel = new MenuPanel(controller);
        lvlPanel = new LvlEndPanel(controller);

        add(gamePanel, CardLayoutGameController.GAME_PANEL);
        add(menuPanel, CardLayoutGameController.MENU_PANEL);
        add(lvlPanel, CardLayoutGameController.LEVEL_PANEL);


        controller.showMenu();
}

CardLayoutGameController

JPanel：

public class CardLayoutGameController implements GameController {
    public static final String GAME_PANEL = "GamePanel";
    public static final String MENU_PANEL = "MenuPanel";
    public static final String LEVEL_PANEL = "LvlPanel";            

    private Container container;
    private CardLayout cardLayout;

    public CardLayoutGameController(Container parent, CardLayout layout) {
        container = parent;
        cardLayout =  layout;
    }

    @Override
    public void showMenu() {
        cardLayout.show(container, MENU_PANEL);
    }

    @Override
    public void showGame() {
        cardLayout.show(container, GAME_PANEL);
    }

    @Override
    public void showEndLvl(){
        cardLayout.show(container, LEVEL_PANEL);
    }
}

然后我添加了两个JPanel类InterfacePanel和GameMainPanel（应该包含此InterfacePanel和我的旧GamePanel）

现在的样子：

UPD 可运行的示例：

可运行的课程：

public class Mcve extends JFrame {

    private GamePanel gamePanel;
    private LvlEndPanel lvlPanel;
    private GameMainPanel gameMainPanel;


    Mcve(){
        CardLayout layout = new CardLayout();

        setLayout(layout);
        GameController controller = new CardLayoutGameController(getContentPane(), layout);

        gamePanel = new GamePanel(controller);  
        lvlPanel = new LvlEndPanel(controller);
        gameMainPanel = new GameMainPanel(controller,this.getContentPane());

        add(gamePanel, CardLayoutGameController.GAME_PANEL);
        add(lvlPanel, CardLayoutGameController.LEVEL_PANEL);
        add(gameMainPanel, CardLayoutGameController.GAME_MAIN_PANEL);
        controller.showMenu();

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setLocationRelativeTo(null);
        setTitle("JavaGame2");
        setResizable(false); 
    }
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame jgame = new Mcve();
                jgame.setVisible(true);
            }
        });
    }
}

GameController：

public interface GameController {
    public void showMenu();
    public void showGame();
    public void showEndLvl();
}

CardLayoutGameController：

public class CardLayoutGameController implements GameController {
    public static final String MENU_PANEL = "MenuPanel";
    public static final String LEVEL_PANEL = "LvlPanel";
    public static final String GAME_MAIN_PANEL = "GameMainPanel";

    private Container container;
    private CardLayout cardLayout;   

    public CardLayoutGameController(Container parent, CardLayout layout) {
        container = parent;
        cardLayout =  layout;        
    }

    @Override
    public void showMenu() {
        cardLayout.show(container, MENU_PANEL);
    }

    @Override
    public void showGame() {
        cardLayout.show(container, GAME_MAIN_PANEL);        
    }

    @Override
    public void showEndLvl(){
        cardLayout.show(container, LEVEL_PANEL);
    }
}

GameMainPanel - 包括2 JPanel＆＃39; s：

public class GameMainPanel extends JPanel {

    private Container container;
    private GameController controller;
    private BorderLayout layout;

    private GamePanel gamePanel;
    private InterfacePanel interfacePanel;

    GameMainPanel(GameController contrl,Container parent){
        controller = contrl;
        container = parent;
        setFocusable(true);
        setBackground(Color.WHITE);
        getPreferredSize();

        gamePanel = new GamePanel(contrl);
        interfacePanel = new InterfacePanel(contrl);

        layout = new BorderLayout();
        setLayout(layout);
        add(gamePanel, BorderLayout.LINE_START);
        add(interfacePanel, BorderLayout.LINE_END);

        addComponentListener(new ComponentAdapter() {
                public void componentShown(ComponentEvent e) {
                        requestFocusInWindow();
                }
        });
    }

    @Override
    public void addNotify() {
        super.addNotify();
        requestFocusInWindow();
    }

     public void paint(Graphics g) {
        super.paint(g);
    }

    public Dimension getPreferredSize() {
        return new Dimension(800, 600);
    }

}

GamePanel：

public class GamePanel extends JPanel {

    private GameController controller;    

    public GamePanel (GameController contrl){        
        controller = contrl;

        addKeyListener(new GameAdapter(contrl));
        setFocusable(true);
        setBackground(Color.BLACK);
        getPreferredSize();        
        addComponentListener(new ComponentAdapter() {

                public void componentShown(ComponentEvent e) {
                        requestFocusInWindow();
                }
            });
    }

    @Override
    public void addNotify() {
        super.addNotify();
        requestFocusInWindow();
    }

    public Dimension getPreferredSize() {
        return new Dimension(650, 600);
    }

    @Override
    public void paint(Graphics g) {
        super.paint(g); 
        Graphics2D g2d = (Graphics2D)g;

        Font small = new Font("Helvetica", Font.BOLD, 24);
        FontMetrics metr = this.getFontMetrics(small);
        g.setColor(Color.GREEN);
        g.setFont(small);
        g.drawString("game",300,300);
    }

    private class GameAdapter extends KeyAdapter{

        private GameController controller;

        GameAdapter(GameController contrl){
            controller = contrl;
        }
        public void keyPressed(KeyEvent e) {
            if ((e.getKeyCode() == KeyEvent.VK_ENTER)) {
                controller.showEndLvl();
            }             
        }
    }
}

InterfacePanel

public class InterfacePanel extends JPanel {

    private GameController controller;    

    InterfacePanel(GameController contrl){
        setFocusable(true);
        setBackground(Color.WHITE);
        getPreferredSize();
        setSize(150,600);

        addComponentListener(new ComponentAdapter() {
                public void componentShown(ComponentEvent e) {
                        requestFocusInWindow();
                }
        });
    }

    @Override
    public void addNotify() {
        super.addNotify();
        requestFocusInWindow();
    }

     public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D)g;

        Font small = new Font("Helvetica", Font.BOLD, 24);
        FontMetrics metr = this.getFontMetrics(small);
        g.setColor(Color.GREEN);
        g.setFont(small);
        g.drawString("interface",10,300);
    }

    public Dimension getPreferredSize() {

        return new Dimension(150, 600);
    }
}

LvlEndPanel：

public class LvlEndPanel extends JPanel{

    private GameController controller;

    public LvlEndPanel(GameController contrl){
        controller = contrl;

        setFocusable(true);
        setBackground(Color.BLACK);
        getPreferredSize();           
        addComponentListener(new ComponentAdapter() {

                public void componentShown(ComponentEvent e) {
                        requestFocusInWindow();
                }
        });

        addKeyListener(new KeyListener() {

            @Override
            public void keyPressed(KeyEvent e) {
                if ((e.getKeyCode() == KeyEvent.VK_ENTER)) {
                            controller.showMenu();
                    }                
            }
            @Override
            public void keyTyped(KeyEvent e) {                
            }
            @Override
            public void keyReleased(KeyEvent e) {                
            }

        });
    }

    @Override
    public void addNotify(){
        super.addNotify();
        requestFocusInWindow();        
    }

     public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D)g;

        Font small = new Font("Helvetica", Font.BOLD, 24);
        FontMetrics metr = this.getFontMetrics(small);
        g.setColor(Color.GREEN);
        g.setFont(small);
        g.drawString("Level Panel",300,300);
    }

     public Dimension getPreferredSize() {        
        return new Dimension(800, 600);
    }
}

MenuPanel：

public class MenuPanel extends JPanel{

    private GameController controller;

    public MenuPanel(GameController contrl){

        setFocusable(true);
        setBackground(Color.WHITE);
        getPreferredSize();
        controller = contrl;

        addComponentListener(new ComponentAdapter() {
                public void componentShown(ComponentEvent e) {
                        requestFocusInWindow();
                }
        });

        addKeyListener(new KeyListener() {

            @Override
            public void keyTyped(KeyEvent e) {
            }

            @Override
            public void keyPressed(KeyEvent e) {
                    if ((e.getKeyCode() == KeyEvent.VK_ENTER)) {
                        controller.showGame();
                    }
            }

            @Override
            public void keyReleased(KeyEvent e) {                
            }

        });

    }

    @Override
    public void addNotify() {
        super.addNotify();
        requestFocusInWindow();
    }


    public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D)g;

        Font small = new Font("Helvetica", Font.BOLD, 24);
        FontMetrics metr = this.getFontMetrics(small);
        g.setColor(Color.GREEN);
        g.setFont(small);
        g.drawString("Game Menu", 300,300);
    }

    public Dimension getPreferredSize() {        
        return new Dimension(800, 600);
    }
}

updend

当我发布这个时，我只有黑框。我怎样才能解决这个问题？我做错了什么？

提前致谢。

感谢您的编辑。

Answer 1

您是控制器将showMenu定义为

public void showMenu() {
    cardLayout.show(container, MENU_PANEL);
}

但是你永远不会添加名称为MENU_PANEL

的任何内容

add(gamePanel, CardLayoutGameController.GAME_PANEL);
add(lvlPanel, CardLayoutGameController.LEVEL_PANEL);
add(gameMainPanel, CardLayoutGameController.GAME_MAIN_PANEL);

将用于gameMainPanel的名称更改为MENU_PANEL或将showMenu更改为使用GAME_MAIN_PANEL而不是

根据示例代码更新

您的布局实际上没有任何问题，（主要）问题是您的MenuPanel paint方法。在可能的情况下，您应该避免在paint方法中加载字体，加载字体的过程可能非常耗时，这会阻止您的面板及时绘制。

相反，可以在构造函数中预加载字体，然后在绘制时应用它，例如......

public class MenuPanel extends JPanel {
    //...
    public MenuPanel(GameController contrl) {
        //...
        Font small = new Font("Helvetica", Font.BOLD, 24);
        setFont(small);
    }

    public void paint(Graphics g) {
        super.paint(g);
        Graphics2D g2d = (Graphics2D) g;

        g.setFont(getFont());
        FontMetrics metr = g.getFontMetrics();
        g.setColor(Color.GREEN);
        g.drawString("Game Menu", 300, 300);
    }
}

这适用于LvlEndPanel，InterfacePanel和GamePanel ......

旁注

addNotify将不再按您配置的方式工作，因为组件只添加一次，而您应该依赖ComponentListener（您是）。更好的解决方案是使用the key bindings API，它可以帮助您克服KeyListener的焦点限制。
通常，您会覆盖paintComponent而不是paint。 paint做了很多很容易被破坏的工作，而其他子组件在重新绘制时会引起问题......

如何将BorderLayout放入CardLayout？

1 个答案: