java - 如何在 JFrame 中分隔面板以分隔类

Question

我有一个名为 MainFrame 的 JFrame，我试图将每个面板分成它自己的类。我尝试过，但由于一些错误而失败。

请查看我尝试过的代码。什么失败了，我做错了什么？

public class MainFrame extends JFrame {

    static Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

    private StartScreenPlayerPanel startScreenPlayerPanel;

    private JPanel contentPane;
    private JTable table;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    MainFrame frame = new MainFrame();
                    System.out.println(screenSize);
                    frame.setMinimumSize(new Dimension(screenSize.width/2, screenSize.height/2));
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public MainFrame() {

        startScreenPlayerPanel = new StartScreenPlayerPanel();

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, (screenSize.width * 2 / 3), (screenSize.height * 2 / 3));
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        GridBagLayout gbl_contentPane = new GridBagLayout();
        gbl_contentPane.columnWidths = new int[]{1200, 0};
        gbl_contentPane.rowHeights = new int[]{74, 0, 446, 0, 0};
        gbl_contentPane.columnWeights = new double[]{1.0, Double.MIN_VALUE};
        gbl_contentPane.rowWeights = new double[]{0.0, 0.0, 1.0, 0.0, Double.MIN_VALUE};
        contentPane.setLayout(gbl_contentPane);

        JLabel lblTitle = new JLabel("The Coin Game",SwingConstants.CENTER);
        lblTitle.setFont(new Font("Arial", Font.PLAIN, (int)screenSize.width/30));
        GridBagConstraints gbc_lblTitle = new GridBagConstraints();
        gbc_lblTitle.gridwidth = 2;
        gbc_lblTitle.insets = new Insets(0, 0, 5, 0);
        gbc_lblTitle.anchor = GridBagConstraints.NORTH;
        gbc_lblTitle.fill = GridBagConstraints.HORIZONTAL;
        gbc_lblTitle.gridx = 0;
        gbc_lblTitle.gridy = 0;
        contentPane.add(lblTitle, gbc_lblTitle);

        JPanel StartScreenBtnPanel = new JPanel();
        GridBagConstraints gbc_StartScreenBtnPanel = new GridBagConstraints();
        gbc_StartScreenBtnPanel.gridwidth = 0;
        gbc_StartScreenBtnPanel.insets = new Insets(0, 0, 5, 0);
        gbc_StartScreenBtnPanel.fill = GridBagConstraints.BOTH;
        gbc_StartScreenBtnPanel.gridx = 0;
        gbc_StartScreenBtnPanel.gridy = 1;
        contentPane.add(StartScreenBtnPanel, gbc_StartScreenBtnPanel);
        StartScreenBtnPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 5, 5));

        JButton btnAddPlayer = new JButton("Add Player");
        btnAddPlayer.setFont(new Font("Tahoma", Font.PLAIN, 16));
        StartScreenBtnPanel.add(btnAddPlayer);

        JButton btnStartGame = new JButton("Start Game");
        btnStartGame.setFont(new Font("Tahoma", Font.PLAIN, 16));
        StartScreenBtnPanel.add(btnStartGame);

我试图将代码分离到不同的类

//      JPanel tblPanel = new JPanel();
//      GridBagConstraints gbc_tblPanel = new GridBagConstraints();
//      gbc_tblPanel.gridwidth = 2;
//      gbc_tblPanel.insets = new Insets(0, 0, 5, 0);
//      gbc_tblPanel.fill = GridBagConstraints.BOTH;
//      gbc_tblPanel.gridx = 0;
//      gbc_tblPanel.gridy = 2;
//      contentPane.add(tblPanel, gbc_tblPanel);
//      tblPanel.setLayout(new BorderLayout(0, 0));

//      table = new JTable();
//      tblPanel.add(table.getTableHeader(), BorderLayout.NORTH);
//      table.getTableHeader().setFont(new Font("Arial", Font.BOLD, 16));
//      table.setModel(new DefaultTableModel(
//          new Object[][] {
//          },
//          new String[] {
//              "New Player", "Initial Points"
//          }
//      ) {
//          Class[] columnTypes = new Class[] {
//              String.class, Integer.class
//          };
//          public Class getColumnClass(int columnIndex) {
//              return columnTypes[columnIndex];
//          }
//      });
//      table.getColumnModel().getColumn(0).setResizable(false);
//      table.getColumnModel().getColumn(0).setMinWidth(14);
//      tblPanel.add(table, BorderLayout.CENTER);

我尝试了什么

在MainFrame类的末尾

contentPane.add(startScreenPlayerPanel, startScreenPlayerPanel.getSSPPConstraints());   
    }
    public StartScreenPlayerPanel getStartScreenPlayerPanel() {
        return startScreenPlayerPanel;
    }

新类 - StartScreenPlayerPanel

public class StartScreenPlayerPanel extends JFrame {
    MainFrame mainframe;

    private JTable table;
    private GridBagConstraints gbc_tblPanel = new GridBagConstraints();

    public StartScreenPlayerPanel() {
        JPanel tblPanel = new JPanel();

        gbc_tblPanel.gridwidth = 2;
        gbc_tblPanel.insets = new Insets(0, 0, 5, 0);
        gbc_tblPanel.fill = GridBagConstraints.BOTH;
        gbc_tblPanel.gridx = 0;
        gbc_tblPanel.gridy = 2;
        tblPanel.setLayout(new BorderLayout(0, 0));

        table = new JTable();
        tblPanel.add(table.getTableHeader(), BorderLayout.NORTH);
        table.getTableHeader().setFont(new Font("Arial", Font.BOLD, 16));
        table.setModel(new DefaultTableModel(new Object[][] {}, new String[] { "New Player", "Initial Points" }) {
            Class[] columnTypes = new Class[] { String.class, Integer.class };

            public Class getColumnClass(int columnIndex) {
                return columnTypes[columnIndex];
            }
        });
        table.getColumnModel().getColumn(0).setResizable(false);
        table.getColumnModel().getColumn(0).setMinWidth(14);
        tblPanel.add(table, BorderLayout.CENTER);


    }

    public GridBagConstraints getSSPPConstraints(){
        return gbc_tblPanel;
    }
}

Answer 1

I'm trying to seperate each panel to it's own class

public class StartScreenPlayerPanel extends JFrame {

好的，那么为什么要扩展 JFrame？

如果您想向主框架添加面板，那么您可以扩展JPanel:

public class StartScreenPlayerPanel extends JPanel {

现在，因为您的类"is"JPanel，所以您只需设置面板的布局管理器并向其添加组件即可。

public StartScreenPlayerPanel() 
{
    setLayout(new BorderLayout());

    table = new JTable();
    table.setModel( ... );

    add(table.getTableHeader(), BorderLayout.NORTH);
    add(table, BorderLayout.CENTER);
}

此类中不需要 getSSPPConstraints() 方法。 “StartScreenPlayerPanel”不知道也不关心面板是如何使用的。它只关心自己类中组件的布局。

结果是一个 JPanel，其中添加了一个 JTable。

注意:通常在使用 JTable 时您会使用:

//add(table.getTableHeader(), BorderLayout.NORTH);
//add(table, BorderLayout.CENTER);
add(new JScrollPane(table), BorderLayout.CENTER);

滚动 Pane 会自动添加表格标题。

现在，在主类中，将面板添加到内容 Pane :

//contentPane.add(startScreenPlayerPanel, startScreenPlayerPanel.getSSPPConstraints()); 
GridBagConstraints gbc_playerPanel = new GridBagConstraints();
gbc_playerPanel.gridwidth = 2;
gbc_playerPanel.insets = new Insets(0, 0, 5, 0);
gbc_playerPanel.fill = GridBagConstraints.BOTH;
gbc_playerPanel.gridx = 0;
gbc_playerPanel.gridy = 2;
contentPane.add(startScreenPlayeerPanel, gbc_playerPanel).

这就是约束是将面板添加到内容面板的类的属性。