如何獲取下個星期日的日期？

Question

可能重複：
ASP.net get the next tuesday

鑑於月中的某一天，我怎麼能得到那一天，下週日？

所以如果我在2011年9月13日星期二通過，它將於9月18日返回。

Answer 1

我使用這個擴展方法：

public static DateTime Next(this DateTime from, DayOfWeek dayOfWeek) 
    { 
     int start = (int)from.DayOfWeek; 
     int target = (int)dayOfWeek; 
     if (target <= start) 
      target += 7; 
     return from.AddDays(target - start); 
    } 

Answer 2

/// <summary> 
/// Finds the next date whose day of the week equals the specified day of the week. 
/// </summary> 
/// <param name="startDate"> 
/// The date to begin the search. 
/// </param> 
/// <param name="desiredDay"> 
/// The desired day of the week whose date will be returneed. 
/// </param> 
/// <returns> 
/// The returned date is on the given day of this week. 
/// If the given day is before given date, the date for the 
/// following week's desired day is returned. 
/// </returns> 
public static DateTime GetNextDateForDay(DateTime startDate, DayOfWeek desiredDay) 
{ 
    // (There has to be a better way to do this, perhaps mathematically.) 
    // Traverse this week 
    DateTime nextDate = startDate; 
    while(nextDate.DayOfWeek != desiredDay) 
     nextDate = nextDate.AddDays(1D); 

    return nextDate; 
} 

來源：

http://angstrey.com/index.php/2009/04/25/finding-the-next-date-for-day-of-week/

Answer 3

date.AddDays(7 - (int)date.DayOfWeek)應該這樣做，我認爲。

date.DayOfWeek將返回一個表示日期的枚舉值（其中0表示星期日）。

Answer 4

 var date = DateTime.Now; 
     var nextSunday = date.AddDays(7 - (int) date.DayOfWeek);  

如果您需要最近的週日，代碼有點不同（如如果你在週日，週日最接近今天）：

var nearestSunday = date.AddDays(7 - date.DayOfWeek == DayOfWeek.Sunday ? 7 : date.DayOfWeek); 

Answer 5

這裏是代碼：

int dayOfWeek = (int) DateTime.Now.DayOfWeek; 
DateTime nextSunday = DateTime.Now.AddDays(7 - dayOfWeek).Date; 

在你的例子中，獲取星期幾的數值：星期二= 2

然後從星期天減去它，7 -2 = 5天加入到下一個星期天的日期。 :)

Answer 6

DateTime dt=dateTime; 
do { 
    dt=dt.AddDays(1); 
} while(dt.DayOfWeek!= DayOfWeek.Sunday); 
// 'dt' is now the next Sunday 

您的問題不清楚如果日期已經是星期日，是否返回相同的日期;我假設不，但如果我錯了，將上面的內容改爲while循環。

Answer 7

實施例使用遞歸

private static DateTime GetNextSunday(DateTime dt) 
    { 
     var tomorrow = dt.AddDays(1); 
     if (tomorrow.DayOfWeek != DayOfWeek.Sunday) 
     { 
      GetNextSunday(tomorrow); 
     } 

     return tomorrow; 
    } 

Answer 8

public static DateTime GetNextSunday (DateTime date) 
{ 
    if (date.DayOfWeek == DayOfWeek.Sunday) 
      date = date.AddDays(1); 
    while (date.DayOfWeek != DayOfWeek.Sunday) 
      date = date.AddDays(1); 

    return date; 
}