c# - 给定月份和年份，如何获取特定周内的一组日期？

Question

如何dates在给定月份和年份的特定周内获得 The ？

例如：

我的参数：

June - 2013  - The second week 

---

我想要这样的结果集：

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

---

我希望它从 Sun 到 Thu 开始。

Answer 1

好吧，在我的Noda Time图书馆中，我会：

• 从上个月末开始
• 循环多次，找到下周日
• 从那里开始，产生日子（所以你可以只使用一个foreach循环）：

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);
    }
}

使用 just DateTime，我可能会从可能是 (week * 7 + 1) 的一个月的第一天开始并循环，直到我找到一周中正确的一天，然后从那里开始：

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);
    }
}

像这样的循环并不是非常有效——你可以计算出提前多少天——但它更明显是正确的。使用更有效的方法，您可以很容易地以一个错误（或回到上个月）结束。当然，如果这很重要，您可以选择更加努力提高效率。

Answer 2

此方法给出一个月中特定星期的天数：

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);
}

这个的输出：

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

将会：

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

注意：我已经编辑了代码。有一个小错误；因为在许多个月中，第一周和最后一周不是完整的周，并且该周的某些天属于另一个月。

Answer 3

如果您对客户端 (JavaScript) 路由感兴趣，那么date.js可能值得一看，它允许以下内容：

// 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');

我发现自然语言语法（即'next thursday'）非常强大。

Answer 4

我还没有真正测试过这个，但我认为这或多或少是你想要的：

        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 5

如果您热衷于使用 linq（我几乎总是如此！），您可以这样做：

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());

Answer 6

尝试这个

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 ##