I have a macro that fires on the "Worksheet_SelectionChange" event. The macro validate data of one column, it changes the background color of the cell if its wrong.
The problem is after run the macro, it clears the history of changes (Ctrl Z) of all the document, even the history changes of other cells that I didnt validate.
How can I solve this problem?
Thanks.
I had this issue and wound up having to create custom undo functionality. It works very similar to the native undo except for the following. I am sure they can be handled with a little more attention.
1) Custom undo does not undo formatting. Only text.
2) Custom undo goes all the way to end of the custom stack. Once this happens the stack is cleared and it does not toggle between the last two items like in the native undo functionality.
2.1) Does not have REDO functionality.
Download a working copy of this code.
VBAProject Layout Screenshot
Module UndoModule
Public UndoStack() As UndoStackEntry
Private Const UndoMaxEntries = 50
Public Sub SaveUndo(ByVal newUndo As UndoStackEntry)
'Save the last undo object
If Not newUndo Is Nothing Then
Call AddUndo(newUndo)
End If
End Sub
Public Sub Undo()
'Appy last undo from the stack and remove it from the array
Dim previousEdit As UndoStackEntry
Set previousEdit = GetLastUndo()
If Not previousEdit Is Nothing Then
Dim previousEventState As Boolean: previousEventState = Application.EnableEvents
Application.EnableEvents = False
Range(previousEdit.Address).Select
Range(previousEdit.Address).Value = previousEdit.Value
Application.EnableEvents = previousEventState
Call RemoveLastUndo
End If
End Sub
Private Function AddUndo(newUndo As UndoStackEntry) As Integer
If UndoMaxEntries < GetCount() Then
Call RemoveFirstUndo
End If
On Error GoTo ErrorHandler
ReDim Preserve UndoStack(UBound(UndoStack) + 1)
Set UndoStack(UBound(UndoStack)) = newUndo
AddUndo = UBound(UndoStack)
ExitFunction:
Exit Function
ErrorHandler:
ReDim UndoStack(0)
Resume Next
End Function
Private Function GetLastUndo() As UndoStackEntry
Dim undoCount As Integer: undoCount = GetCount()
If undoCount > 0 Then
Set GetLastUndo = UndoStack(undoCount - 1)
End If
End Function
Private Function RemoveFirstUndo() As Boolean
On Error GoTo ExitFunction
RemoveFirstUndo = False
Dim i As Integer
For i = 1 To UBound(UndoStack)
Set UndoStack(i - 1) = UndoStack(i)
Next i
ReDim Preserve UndoStack(UBound(UndoStack) - 1)
RemoveFirstUndo = True
ExitFunction:
Exit Function
End Function
Private Function RemoveLastUndo() As Boolean
RemoveLastUndo = False
Dim undoCount As Integer: undoCount = GetCount()
If undoCount > 1 Then
ReDim Preserve UndoStack(undoCount - 2)
RemoveLastUndo = True
ElseIf undoCount = 1 Then
Erase UndoStack
RemoveLastUndo = True
End If
End Function
Private Function GetCount() As Long
GetCount = 0
On Error Resume Next
GetCount = UBound(UndoStack) + 1
End Function
Class Module UndoStackEntry
Public Address As String
Public Value As Variant
Also needed to attach to the following events on the WORKBOOK Excel object.
Public Sub WorkbookUndo()
On Error GoTo ErrHandler
ThisWorkbook.ActiveSheet.PageUndo
ErrExit:
Exit Sub
ErrHandler:
On Error GoTo ErrExit
Application.Undo
Resume ErrExit
End Sub
Finally each sheet where you require undo to work should have the following code attached to its events.
Dim tmpUndo As UndoStackEntry
Dim pageUndoStack() As UndoStackEntry
Private Sub OnSelectionUndoCapture(ByVal Target As Range)
Set tmpUndo = New UndoStackEntry
tmpUndo.Address = Target.Address
tmpUndo.Value = Target.Value
UndoModule.UndoStack = pageUndoStack
End Sub
Private Sub OnChangeUndoCapture(ByVal Target As Range)
Application.OnKey "^{z}", "ThisWorkbook.WorkbookUndo"
Application.OnUndo "Undo Procedure", "ThisWorkbook.WorkbookUndo"
If Not Application.Intersect(Target, Range(tmpUndo.Address)) Is Nothing Then
If Target.Value <> tmpUndo.Value Or Empty = Target.Value Then
UndoModule.UndoStack = pageUndoStack
Call UndoModule.SaveUndo(tmpUndo)
pageUndoStack = UndoModule.UndoStack
End If
End If
End Sub
Public Sub PageUndo()
UndoModule.UndoStack = pageUndoStack
Call UndoModule.Undo
pageUndoStack = UndoModule.UndoStack
End Sub
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
'Stash away the value of the first cell in the selected range
On Error Resume Next
Call OnSelectionUndoCapture(Target)
oldValue = Target.Value
End Sub
Private Sub Worksheet_Change(ByVal Target As Range)
On Error Resume Next
Application.ScreenUpdating = False
Application.EnableEvents = False
If tmpUndo.Value <> Target.Value Then
'Do some stuff
End If
Call OnChangeUndoCapture(Target)
Application.ScreenUpdating = True
Application.EnableEvents = True
End Sub
As the others have stated, there is not way to stop a worksheet-changing macro from clearing the undo stack.
As another side-effect, you can't undo the macro either without writing your own Undo routine, which can be a huge hassle.
Here's to hoping MS changes this in the future.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With