【Java小项目实训】编写一个窗体程序显示的日历 万年历

【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用于显示日期
 * 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

【程序运行效果】

【代码】

package com.practise.Calendar;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Calendar;

import javax.swing.JLabel;

/**
 * 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用于显示日期
 * 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
 * 
 * @author DoubleShift
 *
 */
public class CalendarBean implements ActionListener {

	JLabel now; // 显示当前日期
	JLabel[] label; // 显示日历
	// String[] day;
	int year = 0;
	int month = 0;

	public void setYear(int year) {
		this.year = year;
	}

	public void setMonth(int month) {
		this.month = month;
	}

	@Override
	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(); // 获取当前月份的日历
		for (int i = 0; i < a.length; i++) {
			label[i].setText("          " + a[i]);
		}
	}

	public String[] getCalendar() {

		String[] a = new String[42]; // 6*7
		Calendar rili = Calendar.getInstance();
		rili.set(year, month - 1, 1); // 设置当月一号
		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] = "    "; // 之前设置为空
		}
		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] = "    ";  // 之后设置为空
		}

		return a;
	}

}

package com.practise.Calendar;

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * 
 * @author DoubleShift
 *
 */
public class MyCalendar extends JFrame {

	private static final long serialVersionUID = 1L;

	JButton bx, by, b1, b2, b3, b4, b5, b6, b7;
	CalendarBean cbBean = new CalendarBean();
	JLabel[] label;
	JLabel now;

	public static void main(String[] args) {
		MyCalendar myCalendar = new MyCalendar();
		myCalendar.setSize(500, 400);
		myCalendar.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		myCalendar.setTitle("万年历");
		myCalendar.setVisible(true);
	}

	public MyCalendar() {
		int year, month;
		setLayout(new BorderLayout());

		// 北面設置上月和下月的按钮
		JPanel pNorth = new JPanel();
		cbBean = new CalendarBean();
		cbBean.setYear(2019);
		cbBean.setMonth(12);

		String[] a = cbBean.getCalendar();
		bx = new JButton("上月");
		bx.setActionCommand("lastmonth");
		bx.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				cbBean.actionPerformed(e);
			}
		});

		by = new JButton("下月");
		by.setActionCommand("nextmonth");
		by.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent e) {
				cbBean.actionPerformed(e);
			}
		});

		pNorth.add(bx);
		pNorth.add(by);
		add(pNorth, BorderLayout.NORTH);

		// 面板中间设置日历显示
		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]);
		}
		cbBean.label = this.label;
		for (int i = 0; i < a.length; i++) {
			label[i].setText("          " + a[i]);
		}

		pCenter.setLayout(grid);
		add(pCenter, BorderLayout.CENTER);

		// 面板南面設置当前日期
		JPanel southJPanel = new JPanel();
		now = new JLabel();
		now.setText("日历：" + cbBean.year + "年" + cbBean.month + "月");
		cbBean.now = this.now;
		southJPanel.add(now);
		add(southJPanel, BorderLayout.SOUTH);
	}
}