Question

我正在尝试将字符串转换为日期

a = Datumo: 16.09.2012.

d = Mid(a, 9, 2) ' 16 - should be the day
m = Mid(a, 12, 2) ' 09 - month
y = Mid(a, 15, 4) ' 2012 - year

Dim dt As Date 
dt = DateValue(d, m, y) ' Error line 
dt = DateAdd("d", 1, dt) ' should be 17.09.2012.

我该怎么办呢？

Answer 1

这不正确使用DateValue，替换

dt = DateValue(d, m, y) ' Error line 
dt = DateAdd("d", 1, dt) ' should be 17.09.2012.

与

dt = DateSerial(y, m, d) 
dt = DateAdd("d", 1, dt)

或

dt = 1 + DateAdd("d", 1, dt)

Answer 2

查看DatePart函数;）

来自excel-help：

Dim Datum1 As Date    ' Variablen deklarieren.
Dim Msg
Datum1 = InputBox("Geben Sie ein Datum ein:")
Msg = "Quartal: " & DatePart("q", Datum1)
MsgBox Msg

还有特定的功能来检索有效日期的部分：

Day()
Month()
Year()

来自excel-help的示例：

Dim Datum1, Tag1
Datum1 = #12. Februar 1969#    ' Datum zuweisen.
Tag1 = Day(Datum1)    ' Tag1 enthält 12.

Answer 3

VBA / Excel通常会尝试确定日期并将其弄错。

例如

dt = DateSerial(2012, 14, 42) 'returns #14/03/2013#

dtReal = IsDate("09 / 14 / 2012") 'returns TRUE when we really wanted to test dd/mm/yyyy - there's no 14th month.

我经常使用下面的代码，这是一个更长但更简单的方法，用于确定字符串日期是否真实并将其作为日期返回。

Option Explicit

    Sub test()
    Dim testDate As Boolean
    Dim dt As Date

    testDate = IsTextDate("05/07/2012", dt, "dd/mm/yyyy") 'Could pass "mm/dd/yyyy" instead
    If testDate = True Then
        Debug.Print "Valid Date " & Format(dt, "dd-mmm-yyyy")
    Else
        Debug.Print "Invalid Date"
    End If
    End Sub

    Function IsTextDate(ByVal str As String, ByRef dt As Date, Optional dtFormat As String = "dd/mm/yyyy") As Boolean
    Dim D As Date
    Dim day As Integer
    Dim month As Integer
    Dim year As Long
    Dim daysinFeb As Integer
    Dim dtArray() As String

    'Test input string mask matches date format
    If Not (str Like "##/##/####") Then
        'Debug.Print "Invalid Date"
        Exit Function
    Else
        'split string on delimiter and extract correct 'dd' and 'mm' based on UK/US format
        dtArray = Split(str, "/")
        year = CInt(dtArray(2))
        If dtFormat = "dd/mm/yyyy" Then
            day = CInt(dtArray(0))
            month = CInt(dtArray(1))
        Else
            day = CInt(dtArray(1))
            month = CInt(dtArray(0))
        End If

        'determine days in Feb for year given.
        If IsDate("2/29/" & year) Then
            daysinFeb = 29
        Else
            daysinFeb = 28
        End If

        'determine if date is valid
        Select Case month
            Case 9, 4, 6, 11
                '30 days
                If day <= 30 Then IsTextDate = True

            Case 1, 3, 5, 7, 8, 10, 12
                '31 days
                If day <= 31 Then IsTextDate = True

            Case 2
                'either 28 or 19 days
                If day <= daysinFeb Then IsTextDate = True

        End Select
        If IsTextDate Then dt = DateSerial(year, month, day)

    End If

    End Function

如何将字符串转换为日期

3 个答案: