java 记事本界面_Java图形界面开发之简易记事本代码

以下是一个简单的Java记事本界面的代码，包括文件菜单、编辑菜单和帮助菜单。您可以在此基础上进行修改和完善。

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

public class SimpleNotepad extends JFrame implements ActionListener {
    private JTextArea textArea = new JTextArea();
    private JScrollPane scrollPane = new JScrollPane(textArea);
    private String filename = "";
    
    public SimpleNotepad() {
        // 创建菜单栏
        JMenuBar menuBar = new JMenuBar();
        // 创建文件菜单
        JMenu fileMenu = new JMenu("文件");
        JMenuItem newMenuItem = new JMenuItem("新建");
        JMenuItem openMenuItem = new JMenuItem("打开");
        JMenuItem saveMenuItem = new JMenuItem("保存");
        JMenuItem saveAsMenuItem = new JMenuItem("另存为");
        JMenuItem exitMenuItem = new JMenuItem("退出");
        newMenuItem.addActionListener(this);
        openMenuItem.addActionListener(this);
        saveMenuItem.addActionListener(this);
        saveAsMenuItem.addActionListener(this);
        exitMenuItem.addActionListener(this);
        fileMenu.add(newMenuItem);
        fileMenu.add(openMenuItem);
        fileMenu.add(saveMenuItem);
        fileMenu.add(saveAsMenuItem);
        fileMenu.addSeparator();
        fileMenu.add(exitMenuItem);
        // 创建编辑菜单
        JMenu editMenu = new JMenu("编辑");
        JMenuItem copyMenuItem = new JMenuItem("复制");
        JMenuItem cutMenuItem = new JMenuItem("剪切");
        JMenuItem pasteMenuItem = new JMenuItem("粘贴");
        JMenuItem selectAllMenuItem = new JMenuItem("全选");
        copyMenuItem.addActionListener(this);
        cutMenuItem.addActionListener(this);
        pasteMenuItem.addActionListener(this);
        selectAllMenuItem.addActionListener(this);
        editMenu.add(copyMenuItem);
        editMenu.add(cutMenuItem);
        editMenu.add(pasteMenuItem);
        editMenu.addSeparator();
        editMenu.add(selectAllMenuItem);
        // 创建帮助菜单
        JMenu helpMenu = new JMenu("帮助");
        JMenuItem aboutMenuItem = new JMenuItem("关于");
        aboutMenuItem.addActionListener(this);
        helpMenu.add(aboutMenuItem);
        // 将菜单栏添加到窗口中
        menuBar.add(fileMenu);
        menuBar.add(editMenu);
        menuBar.add(helpMenu);
        setJMenuBar(menuBar);
        // 将文本区域添加到滚动面板中
        scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
        getContentPane().add(scrollPane);
        // 设置窗口属性
        setTitle("简易记事本");
        setSize(600, 400);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }
    
    public void actionPerformed(ActionEvent e) {
        String action = e.getActionCommand();
        if (action.equals("新建")) {
            newFile();
        } else if (action.equals("打开")) {
            openFile();
        } else if (action.equals("保存")) {
            saveFile();
        } else if (action.equals("另存为")) {
            saveAsFile();
        } else if (action.equals("退出")) {
            System.exit(0);
        } else if (action.equals("复制")) {
            textArea.copy();
        } else if (action.equals("剪切")) {
            textArea.cut();
        } else if (action.equals("粘贴")) {
            textArea.paste();
        } else if (action.equals("全选")) {
            textArea.selectAll();
        } else if (action.equals("关于")) {
            JOptionPane.showMessageDialog(this, "简易记事本", "关于", JOptionPane.PLAIN_MESSAGE);
        }
    }
    
    private void newFile() {
        textArea.setText("");
        filename = "";
        setTitle("简易记事本");
    }
    
    private void openFile() {
        JFileChooser fileChooser = new JFileChooser();
        if (fileChooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
            filename = fileChooser.getSelectedFile().getPath();
            setTitle(filename);
            try {
                textArea.setText("");
                java.io.BufferedReader reader = new java.io.BufferedReader(new java.io.FileReader(filename));
                String line = null;
                while ((line = reader.readLine()) != null) {
                    textArea.append(line + "\n");
                }
                reader.close();
            } catch (java.io.IOException e) {
                e.printStackTrace();
            }
        }
    }
    
    private void saveFile() {
        if (filename.equals("")) {
            saveAsFile();
        } else {
            try {
                java.io.PrintWriter writer = new java.io.PrintWriter(new java.io.FileWriter(filename));
                writer.println(textArea.getText());
                writer.close();
            } catch (java.io.IOException e) {
                e.printStackTrace();
            }
        }
    }
    
    private void saveAsFile() {
        JFileChooser fileChooser = new JFileChooser();
        if (fileChooser.showSaveDialog(this) == JFileChooser.APPROVE_OPTION) {
            filename = fileChooser.getSelectedFile().getPath();
            setTitle(filename);
            try {
                java.io.PrintWriter writer = new java.io.PrintWriter(new java.io.FileWriter(filename));
                writer.println(textArea.getText());
                writer.close();
            } catch (java.io.IOException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void main(String[] args) {
        new SimpleNotepad();
    }
}

希望这个简单的记事本界面代码能为您提供参考。