java编写日历程序界面

下面是一个简单的 Java 日历程序界面的示例代码，你可以根据自己的需要进行修改和扩展：

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

public class CalendarGUI extends JFrame implements ActionListener {
    private static final long serialVersionUID = 1L;
    private JLabel currentMonthLabel;
    private JButton prevMonthButton, nextMonthButton;
    private JPanel calendarPanel;
    private int currentYear, currentMonth;

    public CalendarGUI() {
        currentYear = java.time.Year.now().getValue();
        currentMonth = java.time.Month.getValue();

        setTitle("Calendar");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 300);
        setLocationRelativeTo(null);

        // 创建月份标签和按钮
        currentMonthLabel = new JLabel("", JLabel.CENTER);
        prevMonthButton = new JButton("<<");
        nextMonthButton = new JButton(">>");
        prevMonthButton.addActionListener(this);
        nextMonthButton.addActionListener(this);

        // 创建日历面板
        calendarPanel = new JPanel();
        calendarPanel.setLayout(new GridLayout(7, 7));
        calendarPanel.setPreferredSize(new Dimension(220, 120));

        // 添加标签和按钮到顶部面板
        JPanel topPanel = new JPanel();
        topPanel.setLayout(new BorderLayout());
        topPanel.add(currentMonthLabel, BorderLayout.CENTER);
        topPanel.add(prevMonthButton, BorderLayout.WEST);
        topPanel.add(nextMonthButton, BorderLayout.EAST);

        // 添加顶部面板和日历面板到主框架
        add(topPanel, BorderLayout.NORTH);
        add(calendarPanel, BorderLayout.CENTER);

        // 显示日历
        updateCalendar(currentYear, currentMonth);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == prevMonthButton) {
            currentMonth--;
            if (currentMonth == 0) {
                currentMonth = 12;
                currentYear--;
            }
        } else if (e.getSource() == nextMonthButton) {
            currentMonth++;
            if (currentMonth == 13) {
                currentMonth = 1;
                currentYear++;
            }
        }
        updateCalendar(currentYear, currentMonth);
    }

    private void updateCalendar(int year, int month) {
        // 清空日历面板
        calendarPanel.removeAll();

        // 获取当前月份的天数和第一天是星期几
        java.time.YearMonth ym = java.time.YearMonth.of(year, month);
        int daysInMonth = ym.lengthOfMonth();
        int firstDayOfWeek = ym.atDay(1).getDayOfWeek().getValue();

        // 添加星期标签
        String[] weekDays = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
        for (int i = 0; i < weekDays.length; i++) {
            JLabel dayLabel = new JLabel(weekDays[i], JLabel.CENTER);
            calendarPanel.add(dayLabel);
        }

        // 添加空白格子
        for (int i = 1; i < firstDayOfWeek; i++) {
            JLabel dayLabel = new JLabel("", JLabel.CENTER);
            calendarPanel.add(dayLabel);
        }

        // 添加日期标签
        for (int day = 1; day <= daysInMonth; day++) {
            JLabel dayLabel = new JLabel(String.valueOf(day), JLabel.CENTER);
            calendarPanel.add(dayLabel);
        }

        // 刷新标签和按钮
        currentMonthLabel.setText(ym.getMonth().toString() + " " + year);
        currentMonthLabel.repaint();
        prevMonthButton.setEnabled(true);
        nextMonthButton.setEnabled(true);
    }

    public static void main(String[] args) {
        new CalendarGUI().setVisible(true);
    }
}

这个程序使用 Java Swing 组件实现了一个简单的日历界面。它包括一个顶部面板，其中包含了当前月份的标签和前后月份的按钮，以及一个日历面板，用于显示日期。当用户点击前后月份的按钮时，程序会更新日历面板以显示新的日期。