使用JDialog,参照Windows记事本编写一个“字体”对话框

好的，我可以为您提供一些关于JDialog的参考代码来帮助您实现这个“字体”对话框。请注意，以下代码仅供参考，您需要按照您的具体需求进行修改。

首先，您需要创建一个JDialog子类，例如：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

public class FontDialog extends JDialog {

    // 字体选择器和预览文本框
    private JLabel previewLabel;
    private JComboBox<String> fontNameSelector;
    private JComboBox<Integer> fontSizeSelector;
    private JCheckBox boldCheckbox;
    private JCheckBox italicCheckbox;

    // 确定和取消按钮
    private JButton okButton;
    private JButton cancelButton;

    // 对话框返回值
    private String selectedFontName;
    private int selectedFontSize;
    private boolean selectedBold;
    private boolean selectedItalic;

    public FontDialog(Frame parentFrame, String title) {
        super(parentFrame, title);

        // 初始化字体选择器和预览文本框
        previewLabel = new JLabel("Preview Text", JLabel.CENTER);
        previewLabel.setFont(new Font("sans-serif", Font.PLAIN, 14));
        fontNameSelector = new JComboBox<>(GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames());
        fontSizeSelector = new JComboBox<>(new Integer[] { 8, 10, 12, 14, 16, 18, 20, 22, 24 });
        boldCheckbox = new JCheckBox("Bold");
        italicCheckbox = new JCheckBox("Italic");

        // 初始化确定和取消按钮，并设置事件监听器
        okButton = new JButton("OK");
        cancelButton = new JButton("Cancel");
        okButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // 在“确定”按钮被点击时，将当前字体选择器的值保存为对话框的返回值
                selectedFontName = (String) fontNameSelector.getSelectedItem();
                selectedFontSize = (Integer) fontSizeSelector.getSelectedItem();
                selectedBold = boldCheckbox.isSelected();
                selectedItalic = italicCheckbox.isSelected();
                setVisible(false);
            }
        });
        cancelButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // 在“取消”按钮被点击时，将对话框返回值设置为null，并隐藏对话框
                selectedFontName = null;
                selectedFontSize = 0;
                selectedBold = false;
                selectedItalic = false;
                setVisible(false);
            }
        });

        // 将组件添加到对话框中，并设置布局
        JPanel previewPanel = new JPanel(new BorderLayout());
        previewPanel.add(previewLabel, BorderLayout.CENTER);
        previewPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        JPanel inputPanel = new JPanel(new GridLayout(4, 1, 5, 5));
        inputPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        inputPanel.add(fontNameSelector);
        inputPanel.add(fontSizeSelector);
        inputPanel.add(boldCheckbox);
        inputPanel.add(italicCheckbox);
        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT, 10, 10));
        buttonPanel.setBorder(BorderFactory.createEmptyBorder(0, 10, 10, 10));
        buttonPanel.add(okButton);
        buttonPanel.add(cancelButton);
        getContentPane().setLayout(new BorderLayout());
        getContentPane().add(previewPanel, BorderLayout.CENTER);
        getContentPane().add(inputPanel, BorderLayout.NORTH);
        getContentPane().add(buttonPanel, BorderLayout.SOUTH);
        pack();
        setLocationRelativeTo(parentFrame);
    }

    public Font showDialog(Font defaultFont) {
        // 设置字体选择器的默认值
        fontNameSelector.setSelectedItem(defaultFont.getFamily());
        fontSizeSelector.setSelectedItem(defaultFont.getSize());
        boldCheckbox.setSelected(defaultFont.isBold());
        italicCheckbox.setSelected(defaultFont.isItalic());

        // 显示对话框，并等待对话框关闭
        setVisible(true);

        // 根据对话框返回值构造新的字体对象，并返回给调用者
        if (selectedFontName != null) {
            int style = (selectedBold ? Font.BOLD : 0) | (selectedItalic ? Font.ITALIC : 0);
            return new Font(selectedFontName, style, selectedFontSize);
        } else {
            return null;
        }
    }
}

然后，您可以在应用程序中使用该对话框，例如：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;

public class App {

    public static void main(String[] args) {
        JFrame frame = new JFrame("FontDialog Test");
        JTextArea textArea = new JTextArea(10, 30);
        textArea.setFont(new Font("sans-serif", Font.PLAIN, 14));

        JButton fontButton = new JButton("Font...");
        fontButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // 创建一个新的FontDialog，并使用当前文本区域的字体作为默认值
                FontDialog dialog = new FontDialog(frame, "Font Dialog");
                Font defaultFont = textArea.getFont();
                Font selectedFont = dialog.showDialog(defaultFont);
                if (selectedFont != null) {
                    textArea.setFont(selectedFont);
                }
            }
        });

        JPanel panel = new JPanel(new BorderLayout());
        panel.add(new JScrollPane(textArea), BorderLayout.CENTER);
        panel.add(fontButton, BorderLayout.SOUTH);

        frame.getContentPane().add(panel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

希望这个例子能够帮助您完成您的项目！