Java 实训4 编写一个窗体程序显示日历

实训要求：

1.使用BorderLayout 进行总体布局

2.在North 位置放置包含两个按钮( 上月和下月)的Panel

3.在South 位置放置一个Label 用于显示当前年份和月份

4.在Center 位置放置一个显示日历的Panel

5.显示日历的Panel 设置7 行7 列的GridLayout 布局，其中第1行放置7

个按钮显示周“几”，其他6 行放置42 个Label 用于显示期。

6.启动程序时日历中默认显示当前月份的日历。

7.点击“上月”和“下月”可翻看上个月和下个月的日历。

8.程序运行结果如下图:

代码：

CalendaBean.java

import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.util.Calendar;import javax.swing.*;public class CalendaBean implements ActionListener {JLabel[] label;JLabel now;String[] day;int year = 0, month = 0;public void setYear(int year) {this.year = year;}public void setMonth(int month) {this.month = month;}public void actionPerformed(ActionEvent e) {String str = e.getActionCommand();if (str.equals("lastmonth")) {month--;if (month == 0) {month = 12;year--;}}else if (str.equals("nextmonth")) {month++;if (month == 13) {month = 1;year++;}}now.setText("日历:" + year + "年" + month + "月");String[] a = getCalendar();for (int i = 0; i < a.length; i++) {label[i].setText("          "+a[i]);}}public String[] getCalendar() {String[] a = new String[42];Calendar rili = Calendar.getInstance();rili.set(year, month - 1, 1);int weekDay = rili.get(Calendar.DAY_OF_WEEK) - 1;int day = 0;if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8|| month == 10 || month == 12) {day = 31;}if (month == 4 || month == 6 || month == 9 || month == 11) {day = 30;}if (month == 2) {if ((year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0))day = 29;elseday = 28;}for (int i = 0; i < weekDay; i++)a[i] = " ";for (int i = weekDay, n = 1; i < weekDay + day; i++) {a[i] = String.valueOf(n);n++;}for (int i = weekDay + day; i < a.length; i++)a[i] = " ";return a;}}

Test.java

import java.awt.*;import java.awt.event.*;import javax.swing.*;public class Test extends JFrame {JButton b1, b2, b3, b4, b5, b6, b7, bx, by;CalendaBean cb = new CalendaBean();JLabel[] label;JLabel now;public static void main(String[] args) {Test frame = new Test();frame.setSize(500, 400);frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.setTitle("日历");frame.setVisible(true);}public Test() {int year, month;setLayout(new BorderLayout());JPanel pNorth = new JPanel();cb = new CalendaBean();cb.setYear(2017);cb.setMonth(11);String[] a = cb.getCalendar();bx = new JButton("上月");by = new JButton("下月");bx.setActionCommand("lastmonth");by.setActionCommand("nextmonth");bx.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {cb.actionPerformed(e);}});by.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e) {cb.actionPerformed(e);}});pNorth.add(bx);pNorth.add(by);add(pNorth, BorderLayout.NORTH);GridLayout grid = new GridLayout(7, 7);JPanel pCenter = new JPanel();b1 = new JButton("日");b2 = new JButton("一");b3 = new JButton("二");b4 = new JButton("三");b5 = new JButton("四");b6 = new JButton("五");b7 = new JButton("六");pCenter.add(b1);pCenter.add(b2);pCenter.add(b3);pCenter.add(b4);pCenter.add(b5);pCenter.add(b6);pCenter.add(b7);label = new JLabel[42];for (int i = 0; i < 42; i++) {label[i] = new JLabel();pCenter.add(label[i]);}cb.label = this.label;for (int i = 0; i < a.length; i++) {label[i].setText("          "+a[i]);}pCenter.setLayout(grid);add(pCenter, BorderLayout.CENTER);JPanel pSouth = new JPanel();now = new JLabel();now.setText("日历:" + cb.year + "年" + cb.month + "月");cb.now = now;pSouth.add(now);add(pSouth, BorderLayout.SOUTH);}}

运行结果：