当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，并在输入新值时对其进行检查。如果旧值更改为新值，则更新指定单元格中的日期。

我的代码的问题是，我似乎无法找到一种方法来解决这个错误，而不会破坏我的代码，因此我无法修复这一行代码。我知道我的阵列超出界限或者沿着这些界限，但我无法弄清楚如何避开它。

这里是我的代码：

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 

如果它打破，我已经定义，如果旧值更改为新的值，然后更新日期。但它给我一个错误，我找不到解决的办法。

我该如何解决我的代码，使其在范围内，任何建议？

编辑：我现在已经修好了我的代码：

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 ...