Question

我正在尝试在Swing中创建一个表单。

表单应该与此类似：

 ____________________________________
|___________________________________X|
|                                    |
|              ________________      |
|      label1 [________________]     |
|              ________________      |
|      label2 [________________]     |
|                                    |
|                                    |
|                     [Save] [Close] |
|____________________________________|

但是我无法垂直对齐文本字段。

以下是打开框架的代码：

public class Main {

    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                LayoutTest test = new LayoutTest();
                test.setVisible(true);
            }
        });
    }
}

以下是初始化字段和创建布局的代码：

public class LayoutTest {
    private JFrame testFrame;

    JLabel label1;
    JTextField field1;

    JLabel label2;
    JTextField field2;

    JButton saveButton;
    JButton closeButton;

    public LayoutTest() {
        testFrame = new JFrame();

        initProperties();
        initContent();
        initLayout();
    }

    private void initProperties() {
        testFrame.setTitle("Test");
        testFrame.setSize(1000, 800);
        testFrame.setLocationRelativeTo(null);
        testFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }

    private void initContent() {
        label1= new JLabel("Label 1");
        field1= new JTextField(25);
        label1.setLabelFor(field1);

        label2= new JLabel("Label 2");
        field2= new JTextField(25);
        label2.setLabelFor(field2);

        saveButton = new JButton("Save");

        closeButton = new JButton("Close");
        closeButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent event) {
                System.exit(0);
            }
        });

        testFrame.add(label1);
        testFrame.add(field1);
        testFrame.add(label2);
        testFrame.add(field2);
        testFrame.add(saveButton);
        testFrame.add(closeButton);
    }

    private void initLayout() {
        SpringLayout layout = new SpringLayout();

        layout.putConstraint(SpringLayout.NORTH, label1, 10, SpringLayout.NORTH, testFrame.getContentPane());
        layout.putConstraint(SpringLayout.EAST, label1, -5, SpringLayout.WEST, field1);

        layout.putConstraint(SpringLayout.NORTH, field1, 10, SpringLayout.NORTH, testFrame.getContentPane());
        layout.putConstraint(SpringLayout.HORIZONTAL_CENTER, field1, -10, SpringLayout.HORIZONTAL_CENTER, testFrame.getContentPane());

        layout.putConstraint(SpringLayout.NORTH, label2, 10, SpringLayout.SOUTH, label1);
        layout.putConstraint(SpringLayout.EAST, label2, -5, SpringLayout.WEST, field2);

        layout.putConstraint(SpringLayout.NORTH, field2, 5, SpringLayout.SOUTH, field1);
        layout.putConstraint(SpringLayout.HORIZONTAL_CENTER, field2, -10, SpringLayout.HORIZONTAL_CENTER, testFrame.getContentPane());


        layout.putConstraint(SpringLayout.SOUTH, closeButton, -20, SpringLayout.SOUTH, testFrame.getContentPane());
        layout.putConstraint(SpringLayout.EAST, closeButton, -20, SpringLayout.EAST, testFrame.getContentPane());

        layout.putConstraint(SpringLayout.SOUTH, saveButton, -20, SpringLayout.SOUTH, testFrame.getContentPane());
        layout.putConstraint(SpringLayout.EAST, saveButton, -10, SpringLayout.WEST, closeButton);

        testFrame.setLayout(layout);
    }

    public void setVisible(boolean visible) {
        testFrame.setVisible(visible);
    }
}

我尝试将字段添加到面板中，然后在面板上使用SpringLayout.VERTICAL_CENTER，但没有显示任何内容。

如何将字段中心对齐？

Answer 1

使用嵌套面板。类似的东西：

JPanel springPanel = new JPanel(...);
springPanel.add(...);

JPanel center = new JPanel( new GridBagLayout() );
center.add(springPanel, new GridBagConstraints() );

frame.add( center );

Answer 2

根据您的需要，您有多种选择。我更喜欢GridBagLayout，但这是因为我已经使用了15年。

Dialog 01

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FormLayout {

    public static void main(String[] args) {
        new FormLayout();
    }

    public FormLayout() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {

            setLayout(new GridBagLayout());
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.insets = new Insets(8, 8, 8, 8);
            gbc.anchor = GridBagConstraints.EAST;

            add(new JLabel("Label 1"), gbc);
            gbc.gridy++;
            add(new JLabel("Label 2"), gbc);

            gbc.anchor = GridBagConstraints.WEST;
            gbc.gridy = 0;
            gbc.gridx++;
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            add(new JTextField(20), gbc);
            gbc.gridy++;
            add(new JTextField(20), gbc);

            gbc.gridy++;
            gbc.gridx++;
            gbc.gridwidth = 1;
            gbc.anchor = GridBagConstraints.EAST;
            gbc.weightx = 1;
            add(new JButton("Save"), gbc);
            gbc.weightx = 0;
            gbc.gridx++;
            add(new JButton("Close"), gbc);
        }           
    }        
}

对我来说，问题是，当窗口调整大小时，按钮将保持在窗体中间，靠近字段

你可能不介意这一点，但它让我很烦。我更喜欢使用复合布局接近，将内容放在单独的面板中，将按钮放在另一个面板中。这意味着我可以使用三个布局管理器的功能，而不仅仅是一个......

Compound layout

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FormLayout {

    public static void main(String[] args) {
        new FormLayout();
    }

    public FormLayout() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {

            setLayout(new BorderLayout());

            JPanel content = new JPanel(new GridBagLayout());

            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.insets = new Insets(8, 8, 8, 8);
            gbc.anchor = GridBagConstraints.EAST;

            content.add(new JLabel("Label 1"), gbc);
            gbc.gridy++;
            content.add(new JLabel("Label 2"), gbc);

            gbc.anchor = GridBagConstraints.WEST;
            gbc.gridy = 0;
            gbc.gridx++;
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            content.add(new JTextField(20), gbc);
            gbc.gridy++;
            content.add(new JTextField(20), gbc);

            JPanel buttons = new JPanel(new FlowLayout(FlowLayout.RIGHT));    
            buttons.add(new JButton("Save"));
            buttons.add(new JButton("Close"));

            add(content);
            add(buttons, BorderLayout.SOUTH);
        }            
    }        
}

然而，选择是你自己的......

如何在Spring中将一组组件与Swing布局管理器对齐

2 个答案: