如何根据月份和年份获得特定一周中的日期集合？

Question

如何获得dates在给定月份和年份的特定一周？

例如：

我的参数：

June - 2013 - The second week 

---

我想要的结果集是这样的：

9-6-2013 
10-6-2013 
11-6-2013 
12-6-2013 
13-6-2013 

---

我想从太阳开始星期四

Answer 1

在我 Noda Time库我会

好：

• 从的末尾开始上个月
• 无限次循环寻找下一个星期日
• 从那里开始，产生日子（所以你可以只是你知的foreach环路）：

所以：

IEnumerable<LocalDate> GetSundayToWednesday(int year, int month, int week) 
{ 
    LocalDate date = new LocalDate(year, month, 1).PlusDays(-1);   
    for (int i = 0; i < week; i++) 
    { 
     date = date.Next(IsoDayOfWeek.Sunday); 
    } 
    // You always want 4 days, Sunday to Wednesday 
    for (int i = 0; i < 4; i++) 
    { 
     yield return date; 
     date = date.PlusDays(1); 
    } 
} 

只需使用DateTime，我可能会开始在每月的第一天，它可能是（周* 7 + 1）和循环，直到我打了一周的天权，然后再从那里：

IEnumerable<DateTime> GetSundayToWednesday(int year, int month, int week) 
{ 
    // Consider breaking this part out into a separate method? 
    DateTime date = new DateTime(year, month, week * 7 + 1); 
    for (int i = 0; i < 7; i++) 
    { 
     if (date.DayOfWeek == DayOfWeek.Sunday) 
     { 
      break; 
     } 
     date = date.AddDays(1); 
    } 
    // You always want 4 days, Sunday to Wednesday 
    for (int i = 0; i < 4; i++) 
    { 
     yield return date; 
     date = date.AddDays(1); 
    } 
} 

循环这样是不是非常高效的 - 你可以只工作了多少天来推进 - 但更明显的是对。使用更有效的方法很容易导致逐个错误（或回到上个月）。当然，如果这很重要，你可以选择更加努力地提高效率。

Answer 2

我还没有真正测试了这一点，但我认为这确实或多或少你想要什么：

 int year = 2013; 
     int month = 6; 
     int lookupWeek = 2; 

     int daysInMonth = DateTime.DaysInMonth(year, month); 
     int weekCounter = 1; 

     List<DateTime> weekDays = new List<DateTime>(); 

     for (int day = 1; day <= daysInMonth; day++) 
     { 
      DateTime date = new DateTime(year,month,day); 
      if(date.DayOfWeek == DayOfWeek.Sunday && day > 1) weekCounter++; 

      if(weekCounter == lookupWeek) weekDays.Add(date); 
     } 

Answer 3

这种方法使天在一个月的特定星期：

static IEnumerable<string> DaysInWeek(int year, int month, int week) 
{ 
    var date = new DateTime(year, month, 1); 

    var calendar = new GregorianCalendar(); 
    var firstWeek = calendar.GetWeekOfYear(date, CalendarWeekRule.FirstFullWeek, DayOfWeek.Sunday); 
    var days = calendar.GetDaysInMonth(year, month); 

    var daysInWeek = (from day in Enumerable.Range(0, calendar.GetDaysInMonth(year, month) - 1) 
         let dayDate = date.AddDays(day) 
         let week2 = calendar.GetWeekOfYear(dayDate, CalendarWeekRule.FirstFullWeek, DayOfWeek.Sunday) - firstWeek + 1 
         where week2 == week 
         select day + 1).ToList(); 

    foreach (var d in daysInWeek) yield return string.Format("{0:00}-{1:00}-{2:0000}", d, month, year); 
} 

并在此输出：

foreach (var d in DaysInWeek(week, year, month).Take(5)) Log.Info(d); 

是：

09-06-2013 
10-06-2013 
11-06-2013 
12-06-2013 
13-06-2013 

注：我编辑了代码。有一个小错误;因为在很多个月中，第一周和上周都不是完整的周，而那一周的某些日子属于另一个月。

Answer 4

如果你有兴趣的客户端（JavaScript）的路线，然后date.js可能是值得一看，它允许以下：

// What date is next thursday? 
Date.today().next().thursday(); 

// Add 3 days to Today 
Date.today().add(3).days(); 

// Is today Friday? 
Date.today().is().friday(); 

// Number fun 
(3).days().ago(); 

// 6 months from now 
var n = 6; 
n.months().fromNow(); 

// Set to 8:30 AM on the 15th day of the month 
Date.today().set({ day: 15, hour: 8, minute: 30 }); 

// Convert text into Date 
Date.parse('today'); 
Date.parse('t + 5 d'); // today + 5 days 
Date.parse('next thursday'); 
Date.parse('February 20th 1973'); 
Date.parse('Thu, 1 July 2004 22:30:00'); 

我找到自然语言的语法（即“下周四'）相当强大。

Answer 5

试试这个

protected void button_click(object sender, EventArgs e) 
    { 
     DateTime dt = new DateTime(2013, 6, 1); 
     string[] dates = getDates(dt); 

    } 
     public string[] getDates(DateTime dt) 
    { 
     string[] result = new string[7]; ; 
     for (int i = getDay(dt.DayOfWeek.ToString()); i < 7; i++) 
     { 
      if (i == 0) 
      { 
       break; 
      } 
      else 
      { 
       dt = dt.AddDays(1); 
      } 
     } 
     for (int i = 0; i < 7; i++) 
     { 
      dt = dt.AddDays(1); 
      result[i] = dt.ToShortDateString(); 
     } 
     return result; 
    } 
    public int getDay(string day) 
    { 
     switch (day) 
     { 
      case "Monday": 
       return 0; 
      case "Tuesday": 
       return 1; 
      case "Wednesday": 
       return 2; 
      case "Thursday": 
       return 3; 
      case "Friday": 
       return 4; 
      case "Saturday": 
       return 5; 
      case "Sunday": 
       return 6; 
      default: 
       return 0; 
     } 
    }## Heading ## 

Answer 6

如果你热衷于使用LINQ（我几乎总是在这里！），你可以这样做：

int year = 2013; 
int month = 6; 
int weekOfMonth = 2; 

var dates = Enumerable.Range(1, DateTime.DaysInMonth(year, month)) 
        .Select(day => new DateTime(year, month, day)) 
        .GroupBy(g=> g.DayOfYear/7) 
        .ToList(); 

var week = dates.Min(g => g.Key) + weekOfMonth - 1; 
var result = dates.Where(g=> g.Key.Equals(week)).Select(g => g.ToList());