Java GridBagLayout:使组件对齐到左侧
我使用GridBagLayout
进行此布局:
public class Example extends JFrame { public Example() { Border outline = BorderFactory.createLineBorder(Color.black); GridBagLayout gbl = new GridBagLayout(); GridBagConstraints gbc = new GridBagConstraints(); JPanel pane = new JPanel(gbl); gbc.weighty = 1.0; gbc.weightx = 1.0; JLabel unitLbl = new JLabel("Unit"); unitLbl.setBorder(outline); gbc.gridx = 0; gbc.gridy = 0; gbc.ipadx = 30; gbc.ipady = 10; gbl.setConstraints(unitLbl, gbc); pane.add(unitLbl); JLabel typeLbl = new JLabel("Type"); typeLbl.setBorder(outline); gbc.gridx = 0; gbc.gridy = 1; gbc.ipadx = 30; gbc.ipady = 10; gbl.setConstraints(typeLbl, gbc); pane.add(typeLbl); JTextField unitField = new JTextField(); typeLbl.setBorder(outline); gbc.gridx = 1; gbc.gridy = 0; gbc.ipadx = 30; gbc.ipady = 10; gbl.setConstraints(unitField, gbc); pane.add(unitField); String[] type = {"All", "Verb", "Noun", "Adjective"}; JComboBox comboBox = new JComboBox(type); gbc.gridx = 1; gbc.gridy = 1; gbc.ipadx = 30; gbc.ipady = 10; gbl.setConstraints(comboBox, gbc); pane.add(comboBox); add(pane, BorderLayout.CENTER); setSize(new Dimension(400, 300)); getContentPane().setBackground(Color.WHITE); setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { new Example(); } }); } }
在此示例中,运行时,似乎每个组件都位于框架的中心。 但我想要的是:
- 两个
JLabel
(unitLbl
和typelbl
)将位于帧的左侧 -
JTextField
和JComboBox
将分别位于两个JLabel
的右侧,两者之间的距离很小。 - 此外,我想在网格的位置(3,0)添加一个新的
JButton
,但这个位置的高度是两个JLabel
高度的总和。 这意味着,这个按钮高度是“两行”。
如何修复此代码以实现此目标? 请帮帮我。
谢谢 :)
您希望使用GridBagConsraints#anchor
来定义要将组件对齐的单元格内的位置。
要允许组件跨越多个单元格,您需要使用GridBagConstraints#gridwidth
和GridBagConstraints#gridheight
(默认值为1)
public class TestLayout09 { public static void main(String[] args) { new TestLayout09(); } public TestLayout09() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new LayoutPane()); frame.setBackground(Color.WHITE); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } }); } public class LayoutPane extends JPanel { public LayoutPane() { Border outline = BorderFactory.createLineBorder(Color.black); setLayout(new GridBagLayout()); GridBagConstraints gbc = new GridBagConstraints(); // I'm not sure this really is what you want, but I may be mistaken // gbc.weighty = 1.0; // gbc.weightx = 1.0; JLabel unitLbl = new JLabel("Unit"); unitLbl.setBorder(outline); gbc.gridx = 0; gbc.gridy = 0; gbc.ipadx = 30; gbc.ipady = 10; gbc.anchor = GridBagConstraints.WEST; add(unitLbl, gbc); JLabel typeLbl = new JLabel("Type"); typeLbl.setBorder(outline); gbc.gridx = 0; gbc.gridy = 1; gbc.ipadx = 30; gbc.ipady = 10; add(typeLbl, gbc); JTextField unitField = new JTextField(); typeLbl.setBorder(outline); gbc.gridx = 1; gbc.gridy = 0; gbc.ipadx = 30; gbc.ipady = 10; gbc.anchor = GridBagConstraints.EAST; add(unitField, gbc); String[] type = {"All", "Verb", "Noun", "Adjective"}; JComboBox comboBox = new JComboBox (type); gbc.gridx = 1; gbc.gridy = 1; gbc.ipadx = 30; gbc.ipady = 10; add(comboBox, gbc); JButton btn = new JButton("Test"); gbc.gridx = 3; gbc.gridy = 0; gbc.fill = GridBagConstraints.BOTH; gbc.gridheight = 2; add(btn, gbc); } } }
像这样的东西应该做的伎俩:
import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.Insets; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingUtilities; public class Example extends JFrame { public Example() { GridBagLayout gbl = new GridBagLayout(); GridBagConstraints gbc = new GridBagConstraints(); JPanel pane = new JPanel(gbl); gbc.anchor = GridBagConstraints.WEST; JLabel unitLbl = new JLabel("Unit"); gbc.gridx = 0; gbc.gridy = 0; gbc.insets = new Insets(3, 3, 3, 30); gbl.setConstraints(unitLbl, gbc); pane.add(unitLbl); JLabel typeLbl = new JLabel("Type"); gbc.gridx = 0; gbc.gridy = 1; gbl.setConstraints(typeLbl, gbc); pane.add(typeLbl); gbc.weightx = 1.0; gbc.insets = new Insets(3, 3, 3, 3); JTextField unitField = new JTextField(); gbc.gridx = 1; gbc.gridy = 0; gbc.fill = GridBagConstraints.BOTH; gbl.setConstraints(unitField, gbc); pane.add(unitField); String[] type = { "All", "Verb", "Noun", "Adjective" }; JComboBox comboBox = new JComboBox (type); gbc.gridx = 1; gbc.gridy = 1; gbc.fill = GridBagConstraints.NONE; gbl.setConstraints(comboBox, gbc); pane.add(comboBox); final JButton someButton = new JButton("Click me"); someButton.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { JOptionPane.showMessageDialog(someButton, "You have clicked " + someButton.getText()); } }); gbc.gridx = 3; gbc.gridy = 0; gbc.gridheight = 2; gbc.fill = GridBagConstraints.VERTICAL; pane.add(someButton, gbc); add(pane, BorderLayout.CENTER); setSize(new Dimension(400, 300)); getContentPane().setBackground(Color.WHITE); setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { new Example(); } }); } }
- 你需要适当地使用
weightx/weighty
(如何重新分配额外的水平/垂直空间) - 使用适当的
fill
属性(垂直/水平/两者都拉伸的组件?) - 使用适当的
anchor
属性(如果组件未拉伸,或者至少不在两个方向上,它应该在其单元格中的哪个位置) - 我通常更喜欢使用insets而不是padding,因此,我更喜欢使用
ipadx/ipady
insets
(应该在组件周围或组件内部添加额外的空白)
一些答案:
将unitlbl的锚点放到WEST。
gbc.anchor = GridBagConstraints.WEST;
而单位的锚点到EAST。
gbc.anchor = GridBagConstraints.EAST;
对于按钮:
JButton button = new JButton("Test"); gbc.fill = GridBagConstraints.VERTICAL; gbc.gridx = 3; gbc.gridy = 0; gbc.gridwidth = 1; gbc.gridheight = 2; gbc.weighty = 1; pane.add(button, gbc);