Run a Macro every time sheet is changed - vba

Question

i'm still fairly new to macros, i've got a bit of code i need to run on a sheet every time it gets updated, changed, or whatever.
Here is the code I need to run: How can i do this?
Sub UnMergeFill()
Dim cell As Range, joinedCells As Range
For Each cell In ThisWorkbook.ActiveSheet.UsedRange
If cell.MergeCells Then
Set joinedCells = cell.MergeArea
cell.MergeCells = False
joinedCells.Value = cell.Value
End If
Next
End Sub

Answer 1

You can boost the efficiency of your macro by locating the merged cells to process rather than looping through every cell in the Worksheet.UsedRange property and examining it for the Range.MergeCells Property.
Within the worksheet's conventional Range.Find method, there is an option to look for formatting. On this sub-dialog's Alignment tab, you'll find the option to locate Merged cells.
        
This can be incorporated into your VBA sub procedure using the Range.Find method and the Application object's .FindFormat property.
Your sub procedure using FindFormat:
Sub UnMergeFill(Optional ws As Worksheet)
If ws Is Nothing Then Set ws = ActiveSheet
Dim fndMrg As Range, joinedCells As Range
Application.FindFormat.MergeCells = True
With ws
On Error Resume Next
Set fndMrg = .Cells.Find(What:=vbNullString, SearchFormat:=True)
Do While Not fndMrg Is Nothing
Set joinedCells = fndMrg.MergeArea
fndMrg.MergeCells = False
'fndMrg.UnMerge '???
joinedCells.Value = fndMrg.Value
Set fndMrg = .Cells.Find(What:=vbNullString, SearchFormat:=True)
Loop
End With
Application.FindFormat.MergeCells = False
End Sub
Slightly revised Worksheet_Change event macro with more environment shutdown during processing.
Private Sub Worksheet_Change(ByVal Target As Range)
On Error GoTo bm_Safe_Exit
Application.ScreenUpdating = False
Application.EnableEvents = False
Application.DisplayAlerts = False
Call UnMergeFill(Target.Parent)
bm_Safe_Exit:
Application.DisplayAlerts = True
Application.EnableEvents = True
Application.ScreenUpdating = True
End Sub
I've opted to specify the worksheet to be processed rather than rely on the ActiveSheet property. There is the possibility that the Worksheet_Change could be initiated by an outside process when it is NOT the active sheet.
In short, opt for bulk operations whenever possible and avoid looping whenever you can. This is not blinding fast but it should be substantially quicker than looping through the cells.

Answer 2

In the code module for that particular worksheet, just add this:
Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
UnMergeFill
Application.EnableEvents = True
End Sub