java - 公历 GUI - 问题

Question

我必须为我的 Java 类(class)制作一个功能齐全的日历，但我被卡住了。我正在使用 GregorianCalendar 来获取当前的日、月、年等。我正在使用 JButton 来填充填写日历的 42 个字段，并有日期每个月的帖子在每个 JButton 上。我在让月份的第一天(7 月)落入正确的 JButton 时遇到问题。日历将月份识别为 7 月，将年份识别为 2012 年，但它将 1 号放在星期一而不是星期日，并且关闭一周。这是我的代码，感谢您的帮助!

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.util.GregorianCalendar;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Calendar extends JFrame {

    public Calendar() {
        this.setSize(800, 600);
        this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        this.setVisible(true);
        this.setTitle("Calendar");

        JPanel borderPanel = new JPanel();
        borderPanel.setLayout(new BorderLayout());
        getContentPane().add(borderPanel);

        // Initialize GregorianCalendar
        GregorianCalendar cal = new GregorianCalendar();
        int currYear = cal.get(GregorianCalendar.YEAR);
        int currDOM = cal.get(GregorianCalendar.DAY_OF_MONTH);
        int currMnth = cal.get(GregorianCalendar.MONTH);
        String month2 = "";
        switch (currMnth) {
            case 0:
                month2 = "January";
                break;
            case 1:
                month2 = "February";
                break;
            case 2:
                month2 = "March";
                break;
            case 3:
                month2 = "April";
                break;
            case 4:
                month2 = "May";
                break;
            case 5:
                month2 = "June";
                break;
            case 6:
                month2 = "July";
                break;
            case 7:
                month2 = "August";
                break;
            case 8:
                month2 = "September";
                break;
            case 9:
                month2 = "October";
                break;
            case 10:
                month2 = "November";
                break;
            case 11:
                month2 = "December";
                break;
        }
        int nod, som;
        nod = cal.getActualMaximum(GregorianCalendar.DAY_OF_MONTH); //Number of Days
        som = cal.get(GregorianCalendar.DAY_OF_WEEK_IN_MONTH); // Start of the Month

        // Button Layout
        final int ROWS = 6;
        final int COLS = 7;
        JButton[][] days;
        JPanel calendar = new JPanel();
        calendar.setLayout(new GridLayout(6, 7));
        days = new JButton[ROWS][COLS];
        for (int row = 0; row < ROWS; row++) {
            for (int col = 0; col < COLS; col++) {
                days[row][col] = new JButton("");
                calendar.add(days[row][col]);
            }
        }

        // Add Some Number to the Buttons
        int[] tableMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        int startDay = som;
        int daysInMonth = tableMonth[currMnth];
        for (int i = 0; i < daysInMonth; i++) {
            days[(startDay + i) / 7][(startDay + i) % 7].setText("" + (i + 1));
        }
        borderPanel.add(calendar, BorderLayout.CENTER);

        // North Panel - Current Month / Prev & Next Button
        JPanel month = new JPanel();
        month.add(new JButton("Previous"));
        month.add(new JLabel(month2));
        month.add(new JButton("Next"));
        borderPanel.add(month, BorderLayout.NORTH);

        // West Panel - Current Date
        JPanel year = new JPanel();
        year.add(new JButton("The Year is: " + currYear));
        borderPanel.add(year, BorderLayout.SOUTH);

        // South Panel - Current Year
        JPanel today = new JPanel();
        today.add(new JButton("Today is: " + month2 + " " + currDOM + ", " + currYear));
        borderPanel.add(today, BorderLayout.WEST);

    }

    public static void main(String[] args) {
        new Calendar();
    }
}

Answer 1

我会解决您程序的逻辑部分与 GUI 部分分开的问题，然后使用逻辑部分。我会使用 SimpleDateFormat 来获取我的特殊日历字符串，例如月份和星期几字符串。例如:

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class MyCalendar {
   private static final SimpleDateFormat MONTH_FORMAT = new SimpleDateFormat("MMMM");
   private static final SimpleDateFormat DAY_OF_WEEK_FORMAT = new SimpleDateFormat("EEEE");
   private static final SimpleDateFormat MY_DATE_FORMAT = new SimpleDateFormat("MM/dd/yyyy");

   public static void main(String[] args) {


      GregorianCalendar cal = new GregorianCalendar(2012, Calendar.JANUARY, 1);
      for (int j = 0; j < 24; j++) {
         Date date = cal.getTime();
         System.out.println("Date: " + MY_DATE_FORMAT.format(date));
         int year = cal.get(Calendar.YEAR);
         System.out.println("year := " + year);
         int month = cal.get(Calendar.MONTH);
         System.out.printf("month number: %d, month name: %s%n", month, MONTH_FORMAT.format(date));
         int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
         System.out.printf("day of week: %d, day of week string: %s%n", dayOfWeek, DAY_OF_WEEK_FORMAT.format(date));

         int maxDaysInMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
         System.out.println("maxDaysInMonth := " + maxDaysInMonth);
         cal.add(Calendar.MONTH, 1);
         System.out.println();
      }

      System.out.println("Today!");
      cal = new GregorianCalendar(); // today!
      Date date = cal.getTime();
      System.out.println("Date: " + MY_DATE_FORMAT.format(date));
      int year = cal.get(Calendar.YEAR);
      System.out.println("year := " + year);
      int month = cal.get(Calendar.MONTH);
      System.out.printf("month number: %d, month name: %s%n", month, MONTH_FORMAT.format(date));
      int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
      System.out.printf("day of week: %d, day of week string: %s%n", dayOfWeek, DAY_OF_WEEK_FORMAT.format(date));

      int maxDaysInMonth = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
      System.out.println("maxDaysInMonth := " + maxDaysInMonth);
      cal.add(Calendar.MONTH, 1);


   }
}