引用单元格时下标超出范围错误

Question

我的代码的目标是获取单元格的旧值，并根据新值（如果已输入）对其进行检查。如果旧值更改为新值，则更新指定单元格中的日期。

我的代码的问题在于，我似乎无法在不破坏代码的情况下解决此错误，因此我在尝试修复这一行代码时遇到了麻烦。我知道我的数组超出了界限或类似的东西，但我不知道如何绕过它。

这是我的代码：

Dim oldValue()

Public Sub Worksheet_SelectionChange(ByVal Target As Range)
oldValue = Me.Range("D4", "D21").Value
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Me.Range("D4:D21")) Is Nothing Then
    Dim c As Range
    For Each c In Intersect(Target, Me.Range("D4:D21"))
        'Here's where my code is breaking "Subscript out of range error"
        If oldValue(c.Row) <> c.Value Then
            'Update value in column L (8 columns to the right of column D)
            c.Offset(0, 7).Value = Date 'or possibly "= Now()" if you need the time of day that the cell was updated
        End If
    Next
End If
End Sub

在哪里出现问题，我已经定义如果旧值更改为新值，则更新日期。但它给了我一个我找不到解决方法的错误。

如何修复我的代码以使其在范围内，有什么建议吗？

编辑：我现在已经修复了我的代码：

Dim oldValue As Variant

Public Sub Worksheet_SelectionChange(ByVal Target As Range)
'I changed "D4", "D21" to the following:
oldValue = Me.Range("D4:D21").Value
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Me.Range("D4:D21")) Is Nothing Then
    'Application.EnableEvents = False
    Dim c As Range
    For Each c In Intersect(Target, Me.Range("D4:D21"))
        'Check value against what is stored in "oldValue" (row 4 is in position 1, row 5 in position 2, etc)
        'I also changed the array reference
        If oldValue(c.Row - 3, 1) <> c.Value Then
            'Update value in column L (8 columns to the right of column D)
            c.Offset(0, 7).Value = Date 'or possibly "= Now()" if you need the time of day that the cell was updated
        End If
    Next
    'Application.EnableEvents = True
End If
End Sub

Answer 1

Dim oldValue as Variant

....

' oldValue is a 2D array
' and there is a shift between c.Row and the index of oldValue 
If oldValue(c.Row - 3, 1) <> c.Value Then ...