MS Access Change an 'OnChange' Event programmatically in VBA - ms-access

Question

I am working on a project where I have to use MS Access and I have to make the database as loose as possible (Its weird and I dont think best practice but for now given my resources it is what I have).
Anyways I have 50 combo boxes but often have to make changes to one which would mean I have to manually change all of them. Id rather spend hour finding a programming solution then 5 minutes manually doing this.
I need to change the 'OnChange' event using VBA but my code produces an error.
Private Function RunChangePropagate()
Dim combo As ComboBox
RevealGrid
For Each combo In Me.Controls
combo.OnChange = "=ComboBox_Change()"
Next combo
ClearGrid
End Function
Error:
I have also tried making the text to change it to a Variant and then assigning the event to said Variant.
How do I go about doing this?
Thanks in advance.

Answer 1

This is some minimal example, that works:
Public Sub ChangeEvent()
Dim ctrl As Control
For Each ctrl In Me.Controls
If ctrl.Name = "Combo5" Then
Debug.Print ctrl.OnChange
ctrl.OnChange = "SomeProcedure"
End If
Next ctrl
End Sub
In your example you should only remove the = in the assigning. The parenthesis at the end of the assigned sub are not required.

Answer 2

Use WithEvents. This way, you form is completely "detached" from the class controlling (some controls of) the form.
I published an article with links and an example for anyone to study:
Create Windows Phone Colour Palette and Selector using WithEvents
The main code (code behind module and class module) is only:
Option Explicit
' Helper class for form Palette for event handling of textboxes.
' 2017-04-19. Gustav Brock, Cactus Data ApS, CPH.
' Version 1.0.0
' License: MIT.
' *
Private Const EventProcedure As String = "[Event Procedure]"
Private WithEvents ClassTextBox As Access.TextBox
Public Sub Initialize(ByRef TextBox As Access.TextBox)
Set ClassTextBox = TextBox
ClassTextBox.OnClick = EventProcedure
End Sub
Public Sub Terminate()
Set ClassTextBox = Nothing
End Sub
Private Sub ClassTextBox_Click()
' Select full content.
ClassTextBox.SelStart = 0
ClassTextBox.SelLength = Len(ClassTextBox.Value)
' Display the clicked value.
ClassTextBox.Parent!CopyClicked.Value = ClassTextBox.Value
' Copy the clicked value to the clipboard.
DoCmd.RunCommand acCmdCopy
End Sub
and:
Option Explicit
' Form to display the Windows Phone 7.5/8.0 colour theme.
' Also works as a basic example of implementing WithEvents for a form.
' 2017-04-19. Gustav Brock, Cactus Data ApS, CPH.
' Version 1.0.0
' License: MIT.
' *
Private ControlCollection As Collection
Private Sub Form_Load()
' Load events for all colour value textboxes.
Dim EventProcedure As ClassTextboxSelect
Dim Control As Access.Control
Set ControlCollection = New Collection
For Each Control In Me.Controls
If Control.ControlType = acTextBox Then
Set EventProcedure = New ClassTextboxSelect
EventProcedure.Initialize Control
ControlCollection.Add EventProcedure, Control.Name
End If
Next
Set EventProcedure = Nothing
Set Control = Nothing
End Sub
Private Sub Form_Unload(Cancel As Integer)
' Unload events for all colour value textboxes.
Dim EventProcedure As ClassTextboxSelect
For Each EventProcedure In ControlCollection
EventProcedure.Terminate
Next
Set EventProcedure = Nothing
Set ControlCollection = Nothing
End Sub
Full code is also on GitHub: VBA.ModernTheme