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;

else

day = 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：