Question

我需要menuPanel的组件在框架展开时展开。 MenuPanel正在使用GridBayLayout，我已经对面板的填充和重量值进行了修改，但似乎没有任何东西真正导致组件使用框架调整大小。

我怀疑我在display class中添加menuPanel的方式有问题。此外，我还尝试将布局设置为TanksApplication，但这也不起作用。我认为，我不了解一些基本的东西。

主要应用

    public class TanksApplication extends JFrame{ 

       public TanksApplication(){
           super("Tanks");
       }

       public static void main (String args[]){
          Display display = new Display();
          TanksApplication frame = new TanksApplication();
          frame.add(display);
          frame.setSize(600,425);
          frame.setVisible(true);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setLocationRelativeTo(null);
       }
   }

展示班级

public class Display extends JPanel{    
   public Display(){
       menuPanel = new JPanel(new GridBagLayout());
       GridBagConstraints con = new GridBagConstraints();

       mainMenuImageP = new JPanel();
       mainMenuImageP.setBackground(Color.BLACK);
       con.fill = GridBagConstraints.BOTH;
       con.gridy = 0;
       con.gridx = 0;
       con.gridwidth = 2;
       con.weightx = 0.5;
       con.weighty = 0.5;
       con.anchor = GridBagConstraints.CENTER;
       con.ipadx = 400;
       con.ipady = 300;
       con.insets = new Insets(0,20,0,20);
       menuPanel.add(mainMenuImageP, con);

       newGameB = new JButton("New Game");
       con.fill = GridBagConstraints.HORIZONTAL;
       con.gridy = 1;
       con.gridx = 0;
       con.gridwidth = 1;
       con.weightx = 0.5;
       con.weighty = 0.5;
       con.anchor = GridBagConstraints.CENTER;
       con.ipadx = 0;
       con.ipady = 0;
       con.insets = new Insets(10,10,10,10);
       menuPanel.add(newGameB, con);

       loadGameB = new JButton("Load Game");
       con.fill = GridBagConstraints.HORIZONTAL;
       con.gridy = 1;
       con.gridx = 1;
       con.gridwidth = 1;
       con.weightx = 0.5;
       con.weighty = 0.5;
       con.anchor = GridBagConstraints.CENTER;
       con.ipadx = 0;
       con.ipady = 0;
       con.insets = new Insets(10,10,10,10);
       menuPanel.add(loadGameB, con);

       add(menuPanel);
   }

Answer 1

您的问题是您使用menuPanel将GridBagLayout添加到Display JPanel中，后者使用JPanel的默认FlowLayout。 FlowLayout不会调整添加到其中的组件的大小。解决方案：获取menuPanel的 rid ，然后使用Display JPanel。给它一个GridBagLayout并向其添加组件。

在你的展示构建器

中也是如此

setLayout(new GridBagLayout());

删除JPanel menuPanel = new JPanel();以及menuPane.add(...);的任何位置，将其更改为add(...);

例如，

public class Display extends JPanel{    
    public Display(){
        // !! menuPanel = new JPanel(new GridBagLayout());
        GridBagConstraints con = new GridBagConstraints();

        mainMenuImageP = new JPanel();
        mainMenuImageP.setBackground(Color.BLACK);
        con.fill = GridBagConstraints.BOTH;
        con.gridy = 0;
        con.gridx = 0;
        con.gridwidth = 2;
        con.weightx = 0.5;
        con.weighty = 0.5;
        con.anchor = GridBagConstraints.CENTER;
        con.ipadx = 400;
        con.ipady = 300;
        con.insets = new Insets(0,20,0,20);
        // !! menuPanel.add(mainMenuImageP, con);
        add(mainMenuImageP, con); // !!

        newGameB = new JButton("New Game");
        con.fill = GridBagConstraints.HORIZONTAL;
        con.gridy = 1;
        con.gridx = 0;
        con.gridwidth = 1;
        con.weightx = 0.5;
        con.weighty = 0.5;
        con.anchor = GridBagConstraints.CENTER;
        con.ipadx = 0;
        con.ipady = 0;
        con.insets = new Insets(10,10,10,10);
        // !! menuPanel.add(newGameB, con);
        add(newGameB, con); // !!

        loadGameB = new JButton("Load Game");
        con.fill = GridBagConstraints.HORIZONTAL;
        con.gridy = 1;
        con.gridx = 1;
        con.gridwidth = 1;
        con.weightx = 0.5;
        con.weighty = 0.5;
        con.anchor = GridBagConstraints.CENTER;
        con.ipadx = 0;
        con.ipady = 0;
        con.insets = new Insets(10,10,10,10);
        // !! menuPanel.add(loadGameB, con);
        add(loadGameB, con); // !!

        // !! add(menuPanel);
    }

}

请注意，如果这没有帮助，请考虑创建并发布minimal example program或SSCCE。

如何使用GridBagLayout强制JPanels使用JFrame调整大小

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