Question

我想有一个下拉列表，过去20周（例如）。问题在于，可能会遇到另一年。我写的功能（见下文）确实有效，只要没有进入前一年。有没有人在过去20周内填写下拉列表或数组，并考虑到文化？

   Private Sub LoadWeeknumbers()
        Dim ciCurr As CultureInfo = CultureInfo.CurrentCulture
        ' fill the combobox with the last 10 weeks
        ddlWeeknumber.Items.Clear()
        'then the 52 voorbije weken
        For i As Integer = 0 To 52
            Dim week As String = ciCurr.Calendar.GetWeekOfYear(DateTime.Now.AddDays(i * -7), CalendarWeekRule.FirstDay, DayOfWeek.Monday)
            Dim weeknr As String = week + "/" & DateTime.Now.AddDays(i * -7).Year.ToString()
            weeknr = weeknr.Replace("54/", "1/") 'for some reason 54 is in this loop, so we replace it

            ddlWeeknumber.Items.Add("Week: " & weeknr.ToString)
        Next
    End Sub

Answer 1

也许是这样的：

Dim week = GetIso8601WeekOfYear(DateTime.Now)
Dim year = DateTime.Now.Year
For i As Integer = 0 To 19
    ddlWeeknumber.Items.Add("Week: " + week.ToString() + "/" + year.ToString())
    If week = 1 Then
        week = 52
        year -= 1
    Else
        week -= 1
    End If
Next

Public Shared Function GetIso8601WeekOfYear(time As DateTime) As Integer
    Dim day As DayOfWeek = CultureInfo.InvariantCulture.Calendar.GetDayOfWeek(time)
    If day >= DayOfWeek.Monday AndAlso day <= DayOfWeek.Wednesday Then
        time = time.AddDays(3)
    End If

    Return CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(time, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday)
End Function

Answer 2

问题出现在一周开始于一周的中间，所以声明

DateTime.Now.AddDays(i * -7)将在上一年的返回并错过今年的1周

我将代码重写为VB.NET，如下所示。这可以解决问题（对不起，我不是VB.NET）
的专家
Private Sub LoadWeeknumbers() Dim ciCurr As CultureInfo = CultureInfo.CurrentCulture ' fill the combobox with the last 10 weeks ddlWeeknumber.Items.Clear() 'then the 52 voorbije weken Dim weekOverlapped As Boolean = False For i As Integer = 0 To 52 Dim date as DateTime = DateTime.Now.AddDays(i * -7) If date.Year <> DateTime.Now.Year And weekOverlapped <> True date = new DateTime(DateTime.Now.Year, 1, 1) weekOverlapped = True End IF Dim week As String = ciCurr.Calendar.GetWeekOfYear(date , CalendarWeekRule.FirstDay, DayOfWeek.Monday) Dim weeknr As String = week + "/" & date.Year.ToString() weeknr = weeknr.Replace("54/", "1/") 'for some reason 54 is in this loop, so we replace it ddlWeeknumber.Items.Add("Week: " & weeknr.ToString) Next End Sub

Answer 3

感谢您的帮助！

我使用不同的方法成功创建了所需的列表。下面代码的结果是所需的列表，但没有53/2013项。

Private Sub LoadWeeknumbers()
    Dim currentCulture = CultureInfo.CurrentCulture
    Dim week As Integer = currentCulture.Calendar.GetWeekOfYear(DateTime.Now, currentCulture.DateTimeFormat.CalendarWeekRule.FirstFourDayWeek, currentCulture.DateTimeFormat.FirstDayOfWeek)
    Dim weeksAdded = 0
    For i As Integer = week To 1 Step -1
        '  Dim week As String = ciCurr.Calendar.GetWeekOfYear(DateTime.Now.AddDays(i * -7), CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday)
        Dim weeknr As String = i & "/" & DateTime.Now.Year.ToString()
        weeknr = weeknr.Replace("54/", "1/") 'for some reason 54 is in this loop, so we replace it

        ddlWeeknumber.Items.Add("Week: " & weeknr.ToString)
        weeksAdded += 1
    Next i
    'now add another set of weeknumbers to the dropdownlist
    Dim nextDate = New DateTime(DateTime.Now.Year - 1, 12, 27)
    week = currentCulture.Calendar.GetWeekOfYear(nextDate, currentCulture.DateTimeFormat.CalendarWeekRule.FirstFourDayWeek, currentCulture.DateTimeFormat.FirstDayOfWeek)

    For i As Integer = week To 1 Step -1
        If (weeksAdded < 53) Then
            '  Dim week As String = ciCurr.Calendar.GetWeekOfYear(DateTime.Now.AddDays(i * -7), CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday)
            Dim weeknr As String = i & "/" & nextDate.Year.ToString()
            weeknr = weeknr.Replace("54/", "1/") 'for some reason 54 is in this loop, so we replace it

            ddlWeeknumber.Items.Add("Week: " & weeknr.ToString)
            weeksAdded += 1
        End If
    Next i

End Sub

填写下周列表，其中包含过去20周的周数

3 个答案: