如何在GridBagLayout单元格中左右对齐？

我看到GridBagLayout将它的子GridBagLayout定位在单元格中的中心对齐位置。 如何左右对齐？

UPDATE

构造代码（我知道我可以重用c ）

  // button panel JPanel button_panel = new JPanel(); button_panel.add(ok_button); button_panel.add(cancel_button); // placing controls to dialog GridBagConstraints c; GridBagLayout layout = new GridBagLayout(); setLayout(layout); c = new GridBagConstraints(); c.gridx = 0; c.gridy = 0; add(inputSource_label, c); c = new GridBagConstraints(); c.gridx = 1; c.gridy = 0; add(inputSource_combo, c); c = new GridBagConstraints(); c.gridx = 0; c.gridy = 1; add(output_label, c); c = new GridBagConstraints(); c.gridx = 1; c.gridy = 1; add(output_combo, c); c = new GridBagConstraints(); c.gridx = 0; c.gridy = 2; c.gridwidth = 2; add(button_panel, c); 

Answer 1

当使用GridBagLayout进行JLabel：JTextField的表格显示时，我喜欢有一个方法根据x，y位置为我生成GridBagConstraints。 例如：

  private GridBagConstraints createGbc(int x, int y) { GridBagConstraints gbc = new GridBagConstraints(); gbc.gridx = x; gbc.gridy = y; gbc.gridwidth = 1; gbc.gridheight = 1; gbc.anchor = (x == 0) ? GridBagConstraints.WEST : GridBagConstraints.EAST; gbc.fill = (x == 0) ? GridBagConstraints.BOTH : GridBagConstraints.HORIZONTAL; gbc.insets = (x == 0) ? WEST_INSETS : EAST_INSETS; gbc.weightx = (x == 0) ? 0.1 : 1.0; gbc.weighty = 1.0; return gbc; } 

以下代码使GUI看起来像这样：

 import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.Insets; import java.util.HashMap; import java.util.Map; import javax.swing.*; public class GridBagEg { private static void createAndShowGui() { PlayerEditorPanel playerEditorPane = new PlayerEditorPanel(); int result = JOptionPane.showConfirmDialog(null, playerEditorPane, "Edit Player", JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE); if (result == JOptionPane.OK_OPTION) { // TODO: do something with info for (PlayerEditorPanel.FieldTitle fieldTitle : PlayerEditorPanel.FieldTitle.values()) { System.out.printf("%10s: %s%n", fieldTitle.getTitle(), playerEditorPane.getFieldText(fieldTitle)); } } } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGui(); } }); } } @SuppressWarnings("serial") class PlayerEditorPanel extends JPanel { enum FieldTitle { NAME("Name"), SPEED("Speed"), STRENGTH("Strength"); private String title; private FieldTitle(String title) { this.title = title; } public String getTitle() { return title; } }; private static final Insets WEST_INSETS = new Insets(5, 0, 5, 5); private static final Insets EAST_INSETS = new Insets(5, 5, 5, 0); private Map fieldMap = new HashMap(); public PlayerEditorPanel() { setLayout(new GridBagLayout()); setBorder(BorderFactory.createCompoundBorder( BorderFactory.createTitledBorder("Player Editor"), BorderFactory.createEmptyBorder(5, 5, 5, 5))); GridBagConstraints gbc; for (int i = 0; i < FieldTitle.values().length; i++) { FieldTitle fieldTitle = FieldTitle.values()[i]; gbc = createGbc(0, i); add(new JLabel(fieldTitle.getTitle() + ":", JLabel.LEFT), gbc); gbc = createGbc(1, i); JTextField textField = new JTextField(10); add(textField, gbc); fieldMap.put(fieldTitle, textField); } } private GridBagConstraints createGbc(int x, int y) { GridBagConstraints gbc = new GridBagConstraints(); gbc.gridx = x; gbc.gridy = y; gbc.gridwidth = 1; gbc.gridheight = 1; gbc.anchor = (x == 0) ? GridBagConstraints.WEST : GridBagConstraints.EAST; gbc.fill = (x == 0) ? GridBagConstraints.BOTH : GridBagConstraints.HORIZONTAL; gbc.insets = (x == 0) ? WEST_INSETS : EAST_INSETS; gbc.weightx = (x == 0) ? 0.1 : 1.0; gbc.weighty = 1.0; return gbc; } public String getFieldText(FieldTitle fieldTitle) { return fieldMap.get(fieldTitle).getText(); } } 

在这个例子中，我在JOptionPane中显示JPanel，但它可以很容易地显示在JFrame或JApplet或JDialog或...

Answer 2

例如

 public class DimsPanel extends JPanel { public static void main(String[] args){ JFrame main = new JFrame("Dims"); JPanel myPanel = new DimsPanel(); main.setContentPane(myPanel); main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); main.setSize(400, 400); main.setLocationRelativeTo(null); main.setVisible(true); } JButton ok_button = new JButton("OK"), cancel_button = new JButton("Cancel"); JLabel inputSource_label = new JLabel("Input source:"), output_label = new JLabel("Output:"); JComboBox inputSource_combo = new JComboBox(new String[]{"A", "B", "C"}), output_combo = new JComboBox(new String[]{"A", "B", "C"}); public DimsPanel(){ super(new BorderLayout()); Box main = new Box(BoxLayout.Y_AXIS); Dimension labelsWidth = new Dimension(100, 0); JPanel inputPanel = new JPanel(new BorderLayout()); inputSource_label.setPreferredSize(labelsWidth); inputPanel.add(inputSource_label, BorderLayout.WEST); inputPanel.add(inputSource_combo); JPanel outputPanel = new JPanel(new BorderLayout()); output_label.setPreferredSize(labelsWidth); outputPanel.add(output_label, BorderLayout.WEST); outputPanel.add(output_combo); // button panel JPanel button_panel = new JPanel(); button_panel.add(ok_button); button_panel.add(cancel_button); main.add(inputPanel); main.add(outputPanel); add(main, BorderLayout.NORTH); add(button_panel); } } 

你可以跑去看看。 resize就像魅力一样，布局代码只有18行。 唯一的缺点是您需要手动指定标签的宽度。 如果你真的不想在代码中看到setPreferredSize（），那么请成为我的访客并使用GridBag。 但我个人更喜欢这个代码。