java 记事本界面_Java图形界面开发之简易记事本

好的，我了解了你的问题。下面是关于 Java 图形界面开发的简易记事本的界面的代码：

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.filechooser.FileNameExtensionFilter;

public class SimpleNotePad extends JFrame {

    private JTextArea textArea;
    private JButton openButton, saveButton, clearButton;

    public SimpleNotePad() {
        setTitle("简易记事本");
        setSize(600, 500);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        initUI();
    }

    private void initUI() {
        JPanel topPanel = new JPanel();
        openButton = new JButton("打开");
        saveButton = new JButton("保存");
        clearButton = new JButton("清空");
        topPanel.add(openButton);
        topPanel.add(saveButton);
        topPanel.add(clearButton);

        textArea = new JTextArea();
        textArea.setFont(new Font("宋体", Font.PLAIN, 16));
        JScrollPane scrollPane = new JScrollPane(textArea);
        scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

        add(topPanel, BorderLayout.NORTH);
        add(scrollPane, BorderLayout.CENTER);

        openButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                JFileChooser fileChooser = new JFileChooser();
                FileNameExtensionFilter filter = new FileNameExtensionFilter("文本文件", "txt");
                fileChooser.setFileFilter(filter);
                int result = fileChooser.showOpenDialog(SimpleNotePad.this);
                if (result == JFileChooser.APPROVE_OPTION) {
                    File file = fileChooser.getSelectedFile();
                    readTextFile(file);
                }
            }
        });

        saveButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                JFileChooser fileChooser = new JFileChooser();
                FileNameExtensionFilter filter = new FileNameExtensionFilter("文本文件", "txt");
                fileChooser.setFileFilter(filter);
                int result = fileChooser.showSaveDialog(SimpleNotePad.this);
                if (result == JFileChooser.APPROVE_OPTION) {
                    File file = fileChooser.getSelectedFile();
                    writeTextFile(file);
                }
            }
        });

        clearButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                textArea.setText("");
            }
        });
    }

    private void readTextFile(File file) {
        try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
            String line;
            while ((line = reader.readLine()) != null) {
                textArea.append(line);
                textArea.append("\n");
            }
        } catch (IOException ex) {
            JOptionPane.showMessageDialog(this, "打开文件失败！");
        }
    }

    private void writeTextFile(File file) {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(file))) {
            writer.write(textArea.getText());
        } catch (IOException ex) {
            JOptionPane.showMessageDialog(this, "保存文件失败！");
        }
    }

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
            e.printStackTrace();
        }

        SimpleNotePad notePad = new SimpleNotePad();
        notePad.setVisible(true);
    }
}

这个记事本界面非常简单，只有三个按钮：打开、保存和清空。你可以根据需要进行修改和扩展。