面板没有在Java秋千中显示

Question

我已经做了一个Halloffame课程，该课程是Jpanel的子类，我想在此面板上添加标签写作“名人堂”。出现。我试图在框架上添加的每个组件（MainWindow）也会发生同样的情况，除了顶部（用边界layout以北）带有3个按钮。

public class HallOfFame extends JPanel{
JLabel hofLabel;

public HallOfFame() {
    
    
this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
this.setBorder(new LineBorder(Color.GRAY, 1));
this.setAlignmentX(CENTER_ALIGNMENT);

hofLabel = new JLabel("Hall OF Fame");

add(hofLabel);

}

这

public class MainWindow extends JFrame{

/*Size of main window*/
public static final Dimension winSize = new Dimension(1200, 800);
public static final int TOP_HEIGHT = 80;
public static final int PLAYER_WIDTH = 300;


private GameBoard gameBoard;
private HallOfFame hallOfFame;
private BannerPanel bannerPanel;
private PlayerPanel playerPanel;

public MainWindow() {
    
    //Initializing the frame.
    Container c = this.getContentPane();
    c.setPreferredSize(winSize);
    this.setTitle("TucTacToe");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    
    /*Hall of fame*/
    hallOfFame = new HallOfFame();  
    
    /*GameBoard*/
    gameBoard = new GameBoard();
    
    /*Banner Panel*/
    bannerPanel = new BannerPanel();
    
    /*PlayerPanel*/
    playerPanel = new PlayerPanel();
    
    /*Adding the components to the window*/
    c.add(bannerPanel, BorderLayout.NORTH);
    c.add(hallOfFame, BorderLayout.CENTER);
    //add(gameBoard, BorderLayout.CENTER);
    c.add(playerPanel);
    
    this.pack();
    this.setVisible(true);//setting visible the frame.
}

是

项目

Answer 1

c.add(hallOfFame, BorderLayout.CENTER);
c.add(playerPanel)

您将“ PlayerPanel”添加到框架的中心。当您不指定约束时，使用BorderLayout时默认为中心。

仅添加的最后一个组件才能看到。因此，看来您的PlayerPanel没有添加任何组件。

对于简单的测试，只需使用：

c.add(hallOfFame, BorderLayout.CENTER);
//c.add(playerPanel)

现在您应该看到Halloffame面板。