java - GridLayout 之上的 FlowLayout 不起作用

Question

我正在尝试创建一个刽子手游戏，到目前为止它进展顺利，但布局设计似乎并没有到位！字母应该按FlowLayout顺序排列在 Hangman 图片上方，底部有“重新启动”、“帮助”、“添加新单词”和“退出”按钮！我究竟做错了什么？

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;

public class Hangman extends JFrame
{
    int i = 0;
    static JPanel panel;
    static JPanel panel2;
    static JPanel panel3;

    public Hangman()
    {
        JButton[] buttons = new JButton[26];

        panel = new JPanel(new FlowLayout());
        panel2 = new JPanel();
        panel3 = new JPanel();

        JButton btnRestart = new JButton("Restart");
        btnRestart.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {

            }
        });

        JButton btnNewWord = new JButton("Add New Word");
        btnNewWord.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                try
                {
                    FileWriter fw = new FileWriter("Words.txt", true);
                    PrintWriter pw = new PrintWriter(fw, true);

                    String word = JOptionPane.showInputDialog("Please enter a word: ");

                    pw.println(word);
                    pw.close();
                }
                catch(IOException ie)
                {
                    System.out.println("Error Thrown" + ie.getMessage());
                }
            }
        });

        JButton btnHelp = new JButton("Help");
        btnHelp.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                String message = "The word to guess is represented by a row "
                   + "of dashes, giving the number of letters and category of "
                   + "the word. \nIf the guessing player suggests a letter "
                   + "which occurs in the word, the other player writes it "
                   + "in all its correct positions. \nIf the suggested "
                   + "letter does not occur in the word, the other player "
                   + "draws one element of the hangman diagram as a tally mark."
                   + "\n"
                   + "\nThe game is over when:"
                   + "\nThe guessing player completes the word, or guesses "
                   + "the whole word correctly"
                   + "\nThe other player completes the diagram";
               JOptionPane.showMessageDialog(null,message, "Help",JOptionPane.INFORMATION_MESSAGE);
            }
        });

        JButton btnExit = new JButton("Exit");
        btnExit.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                System.exit(0);
            }
        });

        ImageIcon icon = new ImageIcon("D:\\Varsity College\\Prog212Assign1_10-013803\\images\\Hangman1.jpg");
        JLabel label = new JLabel();
        label.setIcon(icon);
        String  b[]=  {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        for(i = 0; i < buttons.length; i++)
        {
            buttons[i] = new JButton(b[i]);

            panel.add(buttons[i]);
        }
        panel2.add(label);

        panel3.add(btnRestart);
        panel3.add(btnNewWord);
        panel3.add(btnHelp);
        panel3.add(btnExit);
    }

    public static void main(String[] args) 
    {
        Hangman frame = new Hangman();
        frame.add(panel, BorderLayout.NORTH);
        frame.add(panel2, BorderLayout.CENTER);
        frame.add(panel3, BorderLayout.SOUTH);
        frame.pack();
        frame.setVisible(true);
    }
}

Answer 1

这里有一些建议：

• 使用 aGridLayout作为顶部面板；在这种情况下，零表示行数由指定的列数和布局中的组件总数决定：

  JPanel north = new JPanel(new GridLayout(0, 9));
  

• 以下是如何使您的中心面板具有合理的初始大小的概述；请注意如何相对于当前大小进行绘制：

  JPanel center = new JPanel() {
  
      private static final int N = 256;
      private static final String S = "Todo...";
  
      @Override
      protected void paintComponent(Graphics g) {
          super.paintComponent(g);
          int dx = (getWidth() - g.getFontMetrics().stringWidth(S)) / 2;
          int dy = getHeight() / 2;
          g.drawString(S, dx, dy);
      }
  
      @Override
      public Dimension getPreferredSize() {
          return new Dimension(N, N);
      }
  };
  

• 您可以像这样构造按钮名称：

  for (int i = 0; i < 26; i++) {
      String letter = String.valueOf((char) (i + 'A'));
      buttons[i] = new JButton(letter);
      north.add(buttons[i]);
  }
  

• 使您的面板实例变量并在事件调度线程上启动：

  EventQueue.invokeLater(new Runnable() {
  
      @Override
      public void run() {
          Hangman frame = new Hangman();
          frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
          frame.add(frame.north, BorderLayout.NORTH);
          frame.add(frame.center, BorderLayout.CENTER);
          frame.add(frame.south, BorderLayout.SOUTH);
          frame.pack();
          frame.setLocationByPlatform(true);
          frame.setVisible(true);
      }
  });
  

Answer 2

如果您进行一些研究，这个问题就会得到很好的记录 - 似乎所有面板（除了 CENTER 面板）在调整大小时都没有重新计算。请参阅如何在其 JSplitPane 中制作此 FlowLayout 包装？ 和http://www.velocityreviews.com/forums/t608472-wrap-flowlayout.html

但是为了快速修复，请尝试将您的main方法更改为此...（基本上使用 BoxLayout 作为您的主容器）

public static void main(String[] args) 
{
    TempProject frame = new TempProject();
    Box mainPanel = Box.createVerticalBox();
    frame.setContentPane(mainPanel);
    mainPanel.add(panel);
    mainPanel.add(panel2);
    mainPanel.add(panel3);
    frame.pack();
    frame.setVisible(true);
}