在那里，我可以用它来从calendarweek /年组合得到一个日期实例，一个简单的内置函数？

应该可以进入 10w2005 到一个文本框，我将创建日期 2005年3月7日从它。

周一应该是第一天，CalendarWeekRule应FirstFullWeek。

我的第一个方法是：

 昏暗W¯¯作为的Int32 = 10
昏暗y为= 2005的Int32
昏暗ð作为新的日期（Y，1，1）
D = d.AddDays（7 *宽）
 

但是，这并不工作，因为FirstDay- CalendarWeekRule不适用。

在此先感谢

修改

这是我已经结束了（感谢fjdumont中的链接）是什么：

 公共共享功能FirstDateOfWeek（BYVAL年为整数，BYVAL WEEKOFYEAR为整数）为DATETIME
      昏暗jan1作为新的日期时间（年，1，1）
      昏暗daysOffset作为整数= CINT（Globalization.CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek） -  CINT（jan1.DayOfWeek）
      昏暗firstWeekDay为DATETIME = jan1.AddDays（daysOffset）
      昏暗curCulture作为System.Globalization.CultureInfo = System.Globalization.CultureInfo.CurrentCulture
      昏暗firstWeek作为整数= curCulture.Calendar.GetWeekOfYear（jan1，curCulture.DateTimeFormat.CalendarWeekRule，curCulture.DateTimeFormat.FirstDayOfWeek）
      如果firstWeek＆LT; = 1，则
          WEEKOFYEAR  -  = 1
      结束如果
      返回firstWeekDay.AddDays（WEEKOFYEAR * 7）
端功能
 

解决方案

这个线程应该有所帮助。你将不得不解析字符串，有点像这一点。

 的String [] SPL = input.ToLower（）斯普利特（W）。
INT年= int.Parse（SPL [1]）;
INT周= int.Parse（SPL [0]）;
 

is there a simple builtin function that i could use to get a date instance from a calendarweek/year-combination?

It should be possible to enter 10w2005 into a TextBox and i'll create the date 07 March 2005 from it.

Monday should be first day and CalendarWeekRule should be FirstFullWeek.

My first approach was:

Dim w As Int32 = 10
Dim y As Int32 = 2005
Dim d As New Date(y, 1, 1)
d = d.AddDays(7 * w)

But this does not work because the FirstDay- CalendarWeekRule are not applied.

Thanks in advance

Edit:

this is what i've ended with(Thanks to fjdumont for the link):

Public Shared Function FirstDateOfWeek(ByVal year As Integer, ByVal weekOfYear As Integer) As DateTime
      Dim jan1 As New DateTime(year, 1, 1)
      Dim daysOffset As Integer = CInt(Globalization.CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek) - CInt(jan1.DayOfWeek)
      Dim firstWeekDay As DateTime = jan1.AddDays(daysOffset)
      Dim curCulture As System.Globalization.CultureInfo = System.Globalization.CultureInfo.CurrentCulture
      Dim firstWeek As Integer = curCulture.Calendar.GetWeekOfYear(jan1, curCulture.DateTimeFormat.CalendarWeekRule, curCulture.DateTimeFormat.FirstDayOfWeek)
      If firstWeek <= 1 Then
          weekOfYear -= 1
      End If
      Return firstWeekDay.AddDays(weekOfYear * 7)
End Function

This thread should help. You will have to parse the string, somewhat like this.

string[] spl = input.ToLower().Split("w");
int year = int.Parse(spl[1]);
int week = int.Parse(spl[0]);