给定个日期 怎么计算它输入给定年份的第几周

Question

比如在文本框内输入2008-12-24 怎样判断12月24号属于2008年的第几周 并且是星期几呢？

Answer 1

static void Main(string[] args)
        {         //如何计算当前日期是本月的第几周？            //得到当前为这个月的第几天
            int day = Convert.ToInt32(DateTime.Now.Day);
            Console.WriteLine("当前是这个月的第" + day + "天");
            //得到是当前年的哪一天
            int yearday = Convert.ToInt32(DateTime.Now.DayOfYear);
            Console.WriteLine(yearday);
            //得到当前年
            int year = Convert.ToInt32(DateTime.Now.Year);
            Console.WriteLine(year);
            //得到月份
            int month = Convert.ToInt32(DateTime.Now.Month);
            int totalDays = 0;
            bool inRn;//是否为闰年
            if (year % 4 == 0 && !(year % 100 == 0) || year % 400 == 0)
            {
                inRn = true;
            }
            else
            {
                inRn = false;//平年
            }
            for (int i = 1900; i < year; i++)
            {
                /* 判断闰年或平年，并进行天数累加 */
                if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0)
                { // 判断是否为闰年
                    totalDays = totalDays + 366; // 闰年366天
                }
                else
                {
                    totalDays = totalDays + 365; // 平年365天
                }
            }
            Console.WriteLine(totalDays);
            int days = 0;
            int beforeDays = 0;
            for (int i = 1; i <= month; i++)
            {
                switch (i)
                {
                    case 1:
                    case 3:
                    case 5:
                    case 7:
                    case 8:
                    case 10:
                    case 12:
                        days = 31;
                        break;
                    case 2:
                        if (inRn)
                        {
                            days = 29;
                        }
                        else
                        {
                            days = 28;
                        }
                        break;
                    default:
                        days = 30;
                        break;
                }
                if (i < month)
                {
                    beforeDays = beforeDays + days;
                }            }
            Console.WriteLine("此月份之前的天数" + beforeDays);
            totalDays = totalDays + beforeDays; // 距离1900年1月1日的天数
            int firstDayOfMonth; // 存储当月第一天是星期几：星期日为0
            int temp = 1 + totalDays % 7; // 从1900年1月1日推算
            if (temp == 7)
            { // 求当月第一天
                firstDayOfMonth = 0; // 周日
            }
            else
            {
                firstDayOfMonth = temp;
            }
            Console.WriteLine("该月第一天是星期" + firstDayOfMonth);        }
//还真没想到这么麻烦

Answer 2

public static void main(String args[]) throws Exception{
//2008-12-24 
    Calendar c = new GregorianCalendar(2008, 12-1, 24);
    System.out.println(c.getTime());
    //属于2008年的第几周
    int weekNum = c.get(Calendar.WEEK_OF_YEAR);
    System.out.println(weekNum);
    //星期几
    int week = c.get(Calendar.DAY_OF_WEEK);
    System.out.println(week);
}

Answer 3

补充一下:
int week = c.get(Calendar.DAY_OF_WEEK);
week返回值从1-7分别对应的是星期日,一,二,...,六

Answer 4

package practice;import java.util.Calendar;
import java.util.Date;public class TryDate{
@SuppressWarnings("deprecation")
public static void main(String[]args){
Calendar c=Calendar.getInstance();
c.setTime(new Date(2008-1900,12-1,24 ));

System.out.println(c.get(Calendar.YEAR));
System.out.println(c.get(Calendar.WEEK_OF_YEAR));
System.out.print(c.get(Calendar.DAY_OF_WEEK));
}

}
试试这个：

Answer 5

有没有人不用calendar,date等和日期、时间有关的类库做出这个题的？

Answer 6

谢谢你！fengzhou0920  我去试试

Answer 7

也得谢谢人家一楼啊！这就是所说的土方法，而不是使用GregorianCalendar工具类来实现