在某些 Excel 版本中无法使用 VBA 更改日期格式

Question

在某些版本的 Excel 中，我有一半的日期格式为 Mar/31/2018，单元格格式一般，另一半是日期格式和 03/31/2018。这些是从某个地方导出的，所以我无法更改。这些日期用于数据透视表。

我试过了

Range("C2:C200").NumberFormat = "m/dd/yyyy"

覆盖格式并将它们全部匹配到相同的格式，但在数据透视表中，上半部分始终显示 Mar/31/2018 而不是 03/31/2018。并且 2018 年 3 月 31 日日期左对齐，而另一半日期右对齐正确格式 03/31/2018。

Range("C2:C200").Value.NumberFormat = "m/dd/yyyy" does not work either. 

For i = 2 to lastRow Step 1
dateString = Cells(i, 3).Value
Cells(i, 3).Value = DateValue(dateString) only works for the cells that are already in custom or date format and not for the general format cells.

我希望能够将一般格式覆盖为适当的日期格式。

Answer 1

Option Explicit

Sub Convert2Date()
    Dim iCt As Integer
    Dim lastRow As Long
    Dim dateStr As Variant
    Dim dateArr() As String
    Dim YearInt As Integer, MonInt As Integer, dayInt As Integer
    'Range("C2:C200").Value.NumberFormat = "m/dd/yyyy" 'does not work either.
    'For i = 2 To lastRow
        'dateString = Cells(i, 3).Value
        'Cells(i, 3).Value = DateValue(dateString) 'only works for the cells that are already in custom or date format and not for the general format cells.


    lastRow = Range("C1").SpecialCells(xlCellTypeLastCell).Row
    For iCt = 2 To lastRow
        dateStr = Cells(iCt, 3).Value
        If Not (dateStr = "") Then
            If IsDate(dateStr) Then
                Cells(iCt, 5) = "isdate = OK!"
                Cells(iCt, 4) = CDate(dateStr)
            Else
                'Cells(iCt, 4) = CDate(dateStr)
                dateArr = Split(dateStr, "/")
                MonInt = ConvertMonth(dateArr(0))
                dayInt = CInt(dateArr(1))
                YearInt = CInt(dateArr(2))
                Cells(iCt, 4).Value = DateSerial(YearInt, MonInt, dayInt)
                Cells(iCt, 5) = "CONVERTED"
                Cells(iCt, 5).Interior.Color = vbYellow
            End If
        End If
    Next iCt
End Sub

Function ConvertMonth(MonthStr As String) As Integer
    Dim tempStr As String
    Dim tempInt As Integer
    tempStr = LCase(MonthStr)
    Select Case tempStr
        Case "jan"
            tempInt = 1
        Case "feb"
            tempInt = 2
        Case "mar"
            tempInt = 3
        Case "apr"
            tempInt = 4
        Case "may"
            tempInt = 5
        Case "jun"
            tempInt = 6
        Case "jul"
            tempInt = 7
        Case "aug"
            tempInt = 8
        Case "sep"
            tempInt = 9
        Case "oct"
            tempInt = 10
        Case "nov"
            tempInt = 11
        Case "dec"
            tempInt = 12
        Case Else
            Debug.Print "undefined month string"
            tempInt = 0
    End Select
End Function

Answer 2

您的某些“日期”可能实际上是 Text 值。将它们转换为常见的“真实”格式。选择单元格并运行：

Sub DateUnifier()
    Dim r As Range, d As Date, s As String, nf As String, arry
    nf = "m/d/yyyy"
    For Each r In Selection
        s = r.Text
        If s <> "" Then
            arry = Split(s, "/")
            If UBound(arry) = 2 Then
                If IsNumeric(arry(0)) Then
                    r.Clear
                    r.Value = DateValue(s)
                    r.NumberFormat = nf
                Else
                    r.Clear
                    r.Value = DateSerial(CInt(arry(2)), konvert(arry(0)), CInt(arry(1)))
                    r.NumberFormat = nf
                End If
            End If
        End If
    Next r
End Sub

Public Function konvert(st As Variant) As Integer
    mnths = Array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
    i = 1
    For Each mn In mnths
        If st = a Then
            konvert = i
            Exit Function
        End If
    Next mn
End Function

更正：

konvert()函数有错误，改用这个：

Public Function konvert(st As Variant) As Integer

    mnths = Array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec")
    i = 1
    For Each mn In mnths
        If st = mn Then
            konvert = i
            Exit Function
        End If
        i = i + 1
    Next mn
End Function