Java Swing GridBagLayout JTextField在添加错误消息后更改大小

我一直在追踪这个bug有一段时间了，但似乎还没弄明白。我有一个带有标签和文本字段列表的小型GUI。在具有label+文本字段的行之间，有一个空行包含一个JLabel，以便根据需要填充错误消息。问题是，当这个错误消息被填充时，它们上面的文本字段由于某种原因被压缩，并且在尝试了几个小时不同的事情之后，我似乎无法找出原因。看起来所有的标签/文本区域彼此之间的压缩程度也略有不同。有人能指出这个问题吗

我已经尝试在面板布局中给每个元素更多的空间。这似乎并没有改变最终结果

如果查看代码，元素位于“continuousTransferPanel”上，“singleTransferPanel”也有相同的问题，只有2行

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这不是一个真正的答案，但我无法用我的尝试重现您的问题。请注意使用数组和集合（此处为映射）来简化代码：

import java.awt.*;
import java.awt.event.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;

@SuppressWarnings("serial")
public class MyPanel extends JPanel {
    public static final String[] LABELS = {"Job Name:", "Source Folder:", "Destination:", "File Regex:"};
    private static final int TF_COLS = 20;
    private static final Font LABEL_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 12);
    private static final Font ERROR_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 8);
    private static final String ERROR_MESSAGE = "Cannot Be Empty";
    private static final Color BACKGROUND = new Color(49, 49, 47);
    private Map<String, JTextField> labelFieldMap = new HashMap<>();
    private Map<String, JLabel> errorLabelMap = new HashMap<>();

    public MyPanel() {
        setLayout(new BorderLayout());
        setBackground(BACKGROUND);

        JPanel labelFieldPanel = new JPanel(new GridBagLayout());
        labelFieldPanel.setOpaque(false);
        for (int i = 0; i < LABELS.length; i++) {
            String text = LABELS[i];
            JLabel label = new JLabel(text);
            JTextField textField = new JTextField(TF_COLS);
            JLabel errorLabel = new JLabel("    ");

            label.setFont(LABEL_FONT);
            label.setForeground(Color.WHITE);
            errorLabel.setFont(ERROR_FONT);
            errorLabel.setForeground(Color.RED);


            labelFieldMap.put(text, textField);
            errorLabelMap.put(text, errorLabel);

            GridBagConstraints gbc = createLabelConstraint(i);
            labelFieldPanel.add(label, gbc);

            gbc = createTextFieldConstraints(i);
            labelFieldPanel.add(textField, gbc);

            gbc = createErrorLabelConstraints(i);
            labelFieldPanel.add(errorLabel, gbc);

            // add blank JLabel at the 0 position
            gbc.gridx = 0;
            labelFieldPanel.add(new JLabel(), gbc); 
        }

        JButton acceptButton = new JButton("Accept");
        acceptButton.setMnemonic(KeyEvent.VK_A);
        acceptButton.addActionListener(e -> {
            for (int i = 0; i < LABELS.length - 1; i++) {
                String text = LABELS[i];
                JTextField textField = labelFieldMap.get(text);
                JLabel errorLabel = errorLabelMap.get(text);
                if (textField.getText().trim().isEmpty()) {
                    errorLabel.setText(ERROR_MESSAGE);
                } else {
                    errorLabel.setText(" ");
                    System.out.println(text + " " + textField.getText());
                }
            }
            System.out.println();
        });
        JPanel btnPanel = new JPanel();
        btnPanel.setOpaque(false);
        btnPanel.add(acceptButton);        

        add(labelFieldPanel, BorderLayout.CENTER);
        add(btnPanel, BorderLayout.PAGE_END);
    }

    private GridBagConstraints createErrorLabelConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i + 1;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(0, 5, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createTextFieldConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.EAST;
        gbc.insets = new Insets(5, 0, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createLabelConstraint(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(5, 5, 0, 5);
        gbc.weightx = 0.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private static void createAndShowGui() {
        MyPanel mainPanel = new MyPanel();

        JFrame frame = new JFrame("MyPanel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}

import java.awt.*；
导入java.awt.event.*；
导入java.util.HashMap；
导入java.util.Map；
导入javax.swing.*；
@抑制警告（“串行”）
公共类MyPanel扩展了JPanel{
公共静态最终字符串[]标签={“作业名称：”，“源文件夹：”，“目标：”，“文件正则表达式：”}；
私有静态最终整数TF_COLS=20；
私有静态最终字体标签\u Font=新字体（Font.SANS\u SERIF，Font.BOLD，12）；
私有静态最终字体错误\u Font=新字体（Font.SANS\u SERIF，Font.BOLD，8）；
私有静态最终字符串错误\u MESSAGE=“不能为空”；
私有静态最终颜色背景=新颜色（49,49,47）；
私有映射labelFieldMap=newHashMap（）；
私有映射errorLabelMap=new HashMap（）；
公共事务委员会（）{
setLayout（新的BorderLayout（））；
挫折背景（背景）；
JPanel labelFieldPanel=新的JPanel（新的GridBagLayout（））；
labelFieldPanel.Set不透明（假）；
对于（int i=0；i{
对于（int i=0；icreateAndShowGui（））；
}
}

结果GUI：

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由于问题出在JTextField的边框上，并且由于无法完全重置默认边框而不出现问题，一种解决方案是为JTextField创建一个复合边框，外边框是一个使用与JPanel背景色相同颜色的线边框，内边框是JTextField的默认边框然后在你的动作监听器中，简单地用crea

import java.awt.*;
import java.awt.event.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;

@SuppressWarnings("serial")
public class MyPanel extends JPanel {
    public static final String[] LABELS = {"Job Name:", "Source Folder:", "Destination:", "File Regex:"};
    private static final int TF_COLS = 20;
    private static final Font LABEL_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 12);
    private static final Font ERROR_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 8);
    private static final String ERROR_MESSAGE = "Cannot Be Empty";
    private static final Color BACKGROUND = new Color(49, 49, 47);
    private Map<String, JTextField> labelFieldMap = new HashMap<>();
    private Map<String, JLabel> errorLabelMap = new HashMap<>();

    public MyPanel() {
        setLayout(new BorderLayout());
        setBackground(BACKGROUND);

        JPanel labelFieldPanel = new JPanel(new GridBagLayout());
        labelFieldPanel.setOpaque(false);
        for (int i = 0; i < LABELS.length; i++) {
            String text = LABELS[i];
            JLabel label = new JLabel(text);
            JTextField textField = new JTextField(TF_COLS);
            JLabel errorLabel = new JLabel("    ");

            label.setFont(LABEL_FONT);
            label.setForeground(Color.WHITE);
            errorLabel.setFont(ERROR_FONT);
            errorLabel.setForeground(Color.RED);


            labelFieldMap.put(text, textField);
            errorLabelMap.put(text, errorLabel);

            GridBagConstraints gbc = createLabelConstraint(i);
            labelFieldPanel.add(label, gbc);

            gbc = createTextFieldConstraints(i);
            labelFieldPanel.add(textField, gbc);

            gbc = createErrorLabelConstraints(i);
            labelFieldPanel.add(errorLabel, gbc);

            // add blank JLabel at the 0 position
            gbc.gridx = 0;
            labelFieldPanel.add(new JLabel(), gbc); 
        }

        JButton acceptButton = new JButton("Accept");
        acceptButton.setMnemonic(KeyEvent.VK_A);
        acceptButton.addActionListener(e -> {
            for (int i = 0; i < LABELS.length - 1; i++) {
                String text = LABELS[i];
                JTextField textField = labelFieldMap.get(text);
                JLabel errorLabel = errorLabelMap.get(text);
                if (textField.getText().trim().isEmpty()) {
                    errorLabel.setText(ERROR_MESSAGE);
                } else {
                    errorLabel.setText(" ");
                    System.out.println(text + " " + textField.getText());
                }
            }
            System.out.println();
        });
        JPanel btnPanel = new JPanel();
        btnPanel.setOpaque(false);
        btnPanel.add(acceptButton);        

        add(labelFieldPanel, BorderLayout.CENTER);
        add(btnPanel, BorderLayout.PAGE_END);
    }

    private GridBagConstraints createErrorLabelConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i + 1;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(0, 5, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createTextFieldConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.EAST;
        gbc.insets = new Insets(5, 0, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createLabelConstraint(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(5, 5, 0, 5);
        gbc.weightx = 0.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private static void createAndShowGui() {
        MyPanel mainPanel = new MyPanel();

        JFrame frame = new JFrame("MyPanel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}

// create JTextField with TF_COLS int column count value
JTextField textField = new JTextField(TF_COLS);

// get the JTextField's default border and make it our inner border
Border innerBorder = textField.getBorder();

// create an outer LineBorder that uses the JPanel's background color
Border outerBorder = BorderFactory.createLineBorder(BACKGROUND);

// create the compound border with these two borders
CompoundBorder myBorder = BorderFactory.createCompoundBorder(outerBorder, innerBorder);

// and set the JTextField's border with it
textField.setBorder(myBorder);

// loop through all the JLabel texts
for (int i = 0; i < LABELS.length; i++) {
    String text = LABELS[i];  // get the array item

    // use it to get the JTextField associated with this String
    JTextField textField = labelFieldMap.get(text);
    // same for the error JLabel
    JLabel errorLabel = errorLabelMap.get(text);

    // get our current JTextField's border which is a compound border
    CompoundBorder myBorder = (CompoundBorder) textField.getBorder();

    // the insideBorder, the original JTextField's border, will be unchanged
    Border insideBorder = myBorder.getInsideBorder();

    // if the text field is empty (and not the last jtext field)
    if (i < LABELS.length - 1 && textField.getText().trim().isEmpty()) {
        errorLabel.setText(ERROR_MESSAGE);  // set the error JLabel

        // set txt field's color if we want
        textField.setBackground(ERROR_BG_COLOR); 

        // okToTransfer = false;

        // create a compound border, the outer border now a line border, RED
        Border outsideBorder = BorderFactory.createLineBorder(Color.RED);
        CompoundBorder newBorder = BorderFactory.createCompoundBorder(outsideBorder, insideBorder);

        // set the JTextField's border to this one
        textField.setBorder(newBorder);
    } else {
        // else all OK
        errorLabel.setText(" ");
        textField.setBackground(Color.WHITE);

        // set the JTextField's border back to our original compound border
        Border outsideBorder = BorderFactory.createLineBorder(BACKGROUND);
        CompoundBorder newBorder = BorderFactory.createCompoundBorder(outsideBorder,
                insideBorder);
        textField.setBorder(newBorder);
    }
    System.out.println(text + " " + textField.getText());
}

import java.awt.*;
import java.awt.Dialog.ModalityType;
import java.awt.event.*;
import java.util.HashMap;
import java.util.Map;
import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.border.CompoundBorder;

@SuppressWarnings("serial")
public class MyPanel extends JPanel {
    public static final String[] LABELS = { "Job Name:", "Source Folder:", "Destination:",
            "File Regex:" };
    private static final int TF_COLS = 30;
    private static final Font LABEL_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 12);
    private static final Font ERROR_FONT = new Font(Font.SANS_SERIF, Font.BOLD, 8);
    private static final String ERROR_MESSAGE = "Cannot Be Empty";
    private static final Color BACKGROUND = new Color(49, 49, 47);
    private static final String TITLE = "File Transfer Job Editor";
    private static final Color TITLE_COLOR = new Color(243, 112, 33);
    private static final Font TITLE_FONT = new Font("Arial", Font.BOLD, 28);
    private static final Color ERROR_BG_COLOR = new Color(255, 220, 220);
    private Map<String, JTextField> labelFieldMap = new HashMap<>();
    private Map<String, JLabel> errorLabelMap = new HashMap<>();

    public MyPanel() {
        JLabel titleLabel = new JLabel(TITLE, SwingConstants.CENTER);
        titleLabel.setForeground(TITLE_COLOR);
        titleLabel.setFont(TITLE_FONT);

        JPanel titlePanel = new JPanel();
        titlePanel.setOpaque(false);
        titlePanel.add(titleLabel);
        titlePanel.setBorder(BorderFactory.createEtchedBorder());

        JPanel labelFieldPanel = new JPanel(new GridBagLayout());
        labelFieldPanel.setOpaque(false);
        int bGap = 3;
        labelFieldPanel.setBorder(BorderFactory.createEmptyBorder(bGap, bGap, bGap, bGap));

        for (int i = 0; i < LABELS.length; i++) {
            String text = LABELS[i];
            JLabel label = new JLabel(text);
            JTextField textField = new JTextField(TF_COLS);
            JLabel errorLabel = new JLabel("    ");
            Border innerBorder = textField.getBorder();
            Border outerBorder = BorderFactory.createLineBorder(BACKGROUND);
            CompoundBorder myBorder = BorderFactory.createCompoundBorder(outerBorder, innerBorder);
            textField.setBorder(myBorder);

            label.setFont(LABEL_FONT);
            label.setForeground(Color.WHITE);
            errorLabel.setFont(ERROR_FONT);
            errorLabel.setForeground(Color.RED);

            labelFieldMap.put(text, textField);
            errorLabelMap.put(text, errorLabel);

            GridBagConstraints gbc = createLabelConstraint(i);
            labelFieldPanel.add(label, gbc);

            gbc = createTextFieldConstraints(i);
            labelFieldPanel.add(textField, gbc);

            gbc = createErrorLabelConstraints(i);
            labelFieldPanel.add(errorLabel, gbc);

            // add blank JLabel at the 0 position
            gbc.gridx = 0;
            labelFieldPanel.add(new JLabel(), gbc);
        }

        JButton acceptButton = new JButton("Accept");
        acceptButton.setMnemonic(KeyEvent.VK_A);
        acceptButton.addActionListener(e -> {
            boolean okToTransfer = true;
            for (int i = 0; i < LABELS.length; i++) {
                String text = LABELS[i];
                JTextField textField = labelFieldMap.get(text);
                JLabel errorLabel = errorLabelMap.get(text);

                CompoundBorder myBorder = (CompoundBorder) textField.getBorder();
                Border insideBorder = myBorder.getInsideBorder();

                if (i < LABELS.length - 1 && textField.getText().trim().isEmpty()) {
                    errorLabel.setText(ERROR_MESSAGE);
                    textField.setBackground(ERROR_BG_COLOR);
                    okToTransfer = false;
                    Border outsideBorder = BorderFactory.createLineBorder(Color.RED);
                    CompoundBorder newBorder = BorderFactory.createCompoundBorder(outsideBorder, insideBorder);
                    textField.setBorder(newBorder);
                } else {
                    errorLabel.setText(" ");
                    textField.setBackground(Color.WHITE);
                    Border outsideBorder = BorderFactory.createLineBorder(BACKGROUND);
                    CompoundBorder newBorder = BorderFactory.createCompoundBorder(outsideBorder, insideBorder);
                    textField.setBorder(newBorder);
                }
                System.out.println(text + " " + textField.getText());
            }
            System.out.println();
            if (okToTransfer) {
                // TODO: transfer code here
                // Window win = SwingUtilities.getWindowAncestor(MyPanel.this);
                // win.dispose();
            }
        });
        JButton cancelBtn = new JButton("Cancel");
        cancelBtn.setMnemonic(KeyEvent.VK_C);
        cancelBtn.addActionListener(e -> {
            Window win = SwingUtilities.getWindowAncestor(MyPanel.this);
            win.dispose();
        });
        int btnPanelGap = 15;
        JPanel btnPanel = new JPanel(new GridLayout(1, 0, btnPanelGap, 0));
        btnPanel.setBorder(BorderFactory.createEmptyBorder(4, btnPanelGap, 4, btnPanelGap));
        btnPanel.setOpaque(false);
        btnPanel.add(acceptButton);
        btnPanel.add(cancelBtn);

        setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
        setBackground(BACKGROUND);
        add(titlePanel);
        add(labelFieldPanel);
        add(btnPanel);
    }

    private GridBagConstraints createErrorLabelConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i + 1;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(0, 5, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createTextFieldConstraints(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.EAST;
        gbc.insets = new Insets(5, 0, 0, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.weightx = 1.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private GridBagConstraints createLabelConstraint(int i) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 2 * i;
        gbc.anchor = GridBagConstraints.WEST;
        gbc.insets = new Insets(5, 5, 0, 5);
        gbc.weightx = 0.0;
        gbc.weighty = 0.0;
        return gbc;
    }

    private static void createAndShowGui() {
        MyPanel mainPanel = new MyPanel();

        JDialog dialog = new JDialog((JFrame) null, "Job Editor", ModalityType.APPLICATION_MODAL);
        dialog.getContentPane().add(mainPanel);
        dialog.setResizable(false);
        dialog.pack();
        dialog.setLocationRelativeTo(null);
        dialog.setVisible(true);
        System.exit(0);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}