java - 边框布局不起作用

Question

我已经尝试设置这个边框布局几个小时了。我查了一下How to Use BorderLayout在Java网站上，但我仍然没有得到它。

我在下面添加了我的代码以供审核，以便更轻松地了解我如何尝试使用 BorderLayout 函数。

如何在 JL3 上设置边框布局？

class GameStructure {
    private String []wordList = {"computer","java","activity","alaska","appearance","article",
            "automobile","basket","birthday","canada","central","character","chicken","chosen",
            "cutting","daily","darkness","diagram","disappear","driving","effort","establish","exact",
            "establishment","fifteen","football","foreign","frequently","frighten","function","gradually",
            "hurried","identity","importance","impossible","invented","italian","journey","lincoln",
            "london","massage","minerals","outer","paint","particles","personal","physical","progress",
            "quarter","recognise","replace","rhythm","situation","slightly","steady","stepped",
            "strike","successful","sudden","terrible","traffic","unusual","volume","yesterday"};
   private JTextField tf;
   private JLabel jl2;

   public void window() {
      ImageIcon ic = new ImageIcon("hangman.png");
      JFrame gameFrame = new JFrame();
      JPanel jp = new JPanel();
      JPanel jpLets = new JPanel();
      JPanel jpBlank = new JPanel();
      JPanel imgPane = new JPanel();
      JPanel panel1 = new JPanel();
      JPanel panel2 = new JPanel();
      panel2.setLayout(new BorderLayout());
      jpLets.setLayout(new BoxLayout(jpLets, BoxLayout.Y_AXIS));
      panel1.setLayout(new BorderLayout());
      panel1.setOpaque(false);//!!
      //jp.setBorder(BorderFactory.createTitledBorder(""));
      tf = new JTextField(1);
      JLabel img = new JLabel(ic, JLabel.CENTER);
      JLabel jl = new JLabel("Enter a letter", JLabel.CENTER);
      jl2 = new JLabel("Letters used:  ", JLabel.CENTER);
      JLabel jl3 = new JLabel("__ ", JLabel.CENTER);
      jl.setFont(new Font("Rockwell", Font.PLAIN, 20));
      tf.setFont(new Font("Rockwell", Font.PLAIN, 20));
      jl2.setFont(new Font("Rockwell", Font.PLAIN, 20));
      imgPane.add(img, BorderLayout.CENTER);
      jp.add(jl);
      jp.add(tf);
      jpLets.add(jl2);
      jpBlank.add(jl3);
      //jpMain.add(imgPane, BorderLayout.CENTER);
      panel1.add(jp, BorderLayout.NORTH);
      panel1.add(jpLets, BorderLayout.SOUTH);
      panel1.add(imgPane);
      panel2.add(panel1, BorderLayout.CENTER);
      panel2.add(jpBlank, BorderLayout.PAGE_END);
      gameFrame.setTitle("Hangman");
      gameFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      gameFrame.setIconImage(
      new ImageIcon("Hangman-Game-grey.png").getImage());
      gameFrame.setResizable(false);
      gameFrame.add(panel2);
      gameFrame.setSize(600, 600);
      gameFrame.setLocationRelativeTo(null);
      gameFrame.setVisible(true);

          int j = 0;
          int []length = new int[64];
          for(j = 0; j<64; j++) {
             length[j] = wordList[j].length();//gets length of words in wordList
          }//end for
          int l = 0;
          String line = "";
          //create line first then put into .setText
          for(int m = 0; m<length[l]; m++) {
              line += "__ ";
              l++;
          }//end for
          jl3.setText(line);

          tf.addActionListener(new ActionListener() {
          @Override
          public void actionPerformed(ActionEvent e) {//when enter key pressed
              JTextField tf = (JTextField)e.getSource();
              String letter = tf.getText();
              jl2.setText(jl2.getText() + letter + " ");//sets jlabel text to users entered letter
              }//end actionPerformed method
          });
      }//end userInput method
   }

public class GameMain {
   public static void main(String[] args) {
      GameStructure game = new GameStructure();
      game.window();
   }
}

Answer 1

首先，让我赞扬您实际查看了我昨天链接给您的教程并努力学习:)

这是我看到的一些事情。

在这里，您尝试将 BorderLayout 用于 JLabel。通常，您希望将 LayoutManager 与容器(JPanel、JFrame、JDialog、JApplet)一起使用。删除下面的代码。

JLabel img = new JLabel(ic, JLabel.CENTER);
img.setLayout( new BorderLayout() );

也在这里，以及您所有的 jp.add()。

jp.add(img, BorderLayout.CENTER);
jp.add(jl);
jp.add(tf);
jp.add(jl2);
....

我假设您想要使用 BorderLayout，但没有为 jp 面板指定 BorderLayout。默认情况下，如果你不指定LayoutManager，JPanel会给你一个FlowLayout

JPanel jp = new JPanel();

请记住，当您将 BorderLayout 分配给容器时，您需要确保添加到其中的每个组件都指定了布局位置。任何位置不得使用多次。此外，通常应始终使用 BorderLayout.CENTER。 (例如，如果面板中只有两个组件，请使用 BorderLayout.SOUTH、BorderLayout.CENTER)。

此外，您应该学习将布局与多个面板嵌套以获得您想要的结果。这是一个简单的例子。假设您有两个按钮和一个图像标签

JLabel label = new JLabel(new ImageIcon(filePath));
JButton jbt1 = new JButton("jbt1");
JButton jbt2 = new JButton("jbt2");

我希望布局看起来像这样

+--------------------------------+
|                                |
|                                |
|          Image Label           |
|                                |
+----------------+---------------+
|      jbt1      |      jbt2     |
+----------------+---------------+

我想做的第一件事是将按钮添加到单独的 JPanel 中。然后将标签包装在 JPanel 中(不是必需的，但我喜欢使用面板)；

JPanel buttonsPanel = new JPanel();     <-- FlowLayout (none specified)
buttonsPanel.add(jbt1);
buttonsPanel.add(jbt2);

JPanel labelPanel = new JPanle();       <-- FlowLayout
labelPabel.add(label);

然后我将使用 BorderLayout 将这两个面板与另一个面板包裹起来

JPanel panel1 = new JPanel(new BorderLayout());
panel1.add(buttonPanel, BorderLayout.SOUTH);
panel1.add(labelPanel, BorderLayout.CENTER);

所以我的最终面板看起来像这样

            panel1
+--------------------------------+
|                                |
|                                |   BorderLayout.CENTER
|          Image Label           |
|                                |
+----------------+---------------+
|      jbt1      |      jbt2     |   BorderLayout.SOUTH
+----------------+---------------+

假设您想出了另一个想要添加的面板。您想要将此新面板添加到我们刚刚创建的面板的左侧。我们现在只需要使用我们创建的 panel1 面板，并将该面板和新面板包装在另一个面板中

JPanel newPanel = new JPanel();

JPanel panel2 new JPanel(new BorderLayout());
panel2.add(newPanel, BorderLayout.WEST);
panel2.add(panel1, BorderLayout.CENTER);

             panel2
+---------------+--------------------------------+
|               |                                |
|               |                                |  
|               |          Image Label           |
|    newPanel   |                                |
|               +----------------+---------------+
|               |      jbt1      |      jbt2     |   
+---------------+----------------+---------------+

看看布局和面板如何。这是处理组件布局的好方法