通过年月周查询查询本周有哪些天
这是今天做一个计划统计写的一个简单算法，通过年,月,周计算出本周有哪些天，测试效果图如下：
第一步：获取本月第一周第一个工作日
View Code
1 /// <summary>
2 /// 获取本月第一周第一个工作日
3 /// </summary>
4 /// <param name="weekEnum">本月一号在这一周星期几</param>
5 /// <returns>本月第一周第一个工作日</returns>
6 private int GetFirstWeekDayWithMonth(DayOfWeek weekEnum)
7 {
8 if (weekEnum.GetHashCode() == 1)
9 return 1;
10 else if (weekEnum.GetHashCode() == 0)
11 return 2;
12 else
13 return 7 - weekEnum.GetHashCode() + 2;
14 }
第二步：获取本月最后一个工作日
View Code
1 /// <summary>
2 /// 获取本月最后一天
3 /// </summary>
4 /// <param name="year">年</param>
5 /// <param name="month">月</param>
6 /// <returns>本月最后一个工作日</returns>
7 private int GetLastDayWithMonth(int year, int month)
8 {
9 int maxDay = 1;
10 switch (month)
11 {
12 case 1:
13 case 3:
14 case 5:
15 case 7:
16 case 8:
17 case 10:
18 case 12:
19 maxDay = 31;
20 break;
21 case 2:
22 if (year % 4 == 0) maxDay = 29; else maxDay = 28;
23 break;
24 case 4:
25 case 6:
26 case 9:
27 case 11:
28 maxDay = 30;
29 break;
30 default:
31 return maxDay;
32 }
33 return maxDay;
34 }
第三步：计算
View Code
1 /// <summary>
2 /// 根据年月周计算时间
3 /// </summary>
4 /// <param name="year">年</param>
5 /// <param name="month">月</param>
6 /// <param name="week">周</param>
7 /// <returns>DateTime[]时间</returns>
8 public DateTime[] GetDaysByWeekAndMont(int year, int month, int week)
9 {
10 int firstDay = 0;
11 DateTime[] days = new DateTime[] { new DateTime() };
12 if (month < 13 && week < 6)
13 {
14 DateTime date = new DateTime(year, month, 1);
15 firstDay = GetFirstWeekDayWithMonth(date.DayOfWeek) + 7 * (week - 1);
16 if (firstDay <= GetLastDayWithMonth(year, month))
17 {
18 days = new DateTime[7];
19 for (int i = 0; i < 7; i++)
20 {
21 if (firstDay <= GetLastDayWithMonth(year, month) && month < 13)
22 days[i] = new DateTime(year, month, firstDay++);
23 else if (firstDay >= GetLastDayWithMonth(year, month) && month < 13)
24 {
25 firstDay = 1;
26 if (month != 12)
27 days[i] = new DateTime(year, ++month, firstDay++);
28 else
29 {
30 month = 1;
31 days[i] = new DateTime(++year, month++, firstDay++);
32 }
33 }
34 else if (firstDay <= GetLastDayWithMonth(year, month) && month > 12)
35 {
36 days[i] = new DateTime(year, month, firstDay++);
37 }
38 else if (firstDay >= GetLastDayWithMonth(year, month) && month > 12)
39 {
40 month = 1; firstDay = 1;
41 days[i] = new DateTime(year, month++, firstDay++);
42 }
43 }
44 }
45 else
46 throw new Exception(year.ToString() + "年" + month + "月没有第" + week + "周"); //Console.WriteLine("输入时间错误");
47 }
48 else if (month > 12 )
49 throw new Exception(year + "年没有" + month + "月");//Console.WriteLine("输入时间错误");
50 else if (month < 13 && week > 5)
51 throw new Exception(year + "年" + month + "月没有第" + week + "周");
52 return days;
53 }
