Error handling for merging cells in Excel VBA

Question

I'm currently developing an add-in for Excel which will automatically format a table. The users has to follow the specific format when preparing the table, or else the common error of "Merging cells only keeps the upper-left cell value, and discards the other values." is bound to appear.

I would like to mute this alert from Excel, but would still like to catch this error and pass a different message to the users to terminate this sub. I've tried this:

Sub FormatTable()
    On Error Goto ErrHandler
    Application.DisplayAlerts = False
    'Codes for formatting the table
    Exit Sub
ErrHandler:
    MsgBox "Incorrect formatting. Terminating process to conserve data."
End Sub

However, I do realise that using "Application.DisplayAlerts = False" will cause Excel to choose the default action and proceed to merge the cells which causes a big mess. It will not go the ErrHandler. Is there some way for making this happen? Thank you.

Answer 1

You could test for merged cells in the selected range prior to running your code:

Public Function HasMergedCells(oRng As Range)
    Dim oCell As Range
    Dim oArea As Range
    For Each oArea In oRng.Areas
        For Each oCell In oArea.Cells
            If oCell.MergeArea.MergeCells Then
                HasMergedCells = True
                Exit Function
            End If
        Next
    Next
End Function