Access 2010 combobox events do not trigger at all

Question

In Access 2010, I am struggling with making a combobox force users to give it input on a data entry form. In this case, I want the combobox to detect that the user has made no selection at all.

I've put the included code in the OnClick, BeforeUpdate, and OnChange events of cbo_Event1. cmb_StartOfSeason, cmb_EndOfSeason, and cmb_MoneyRequired are comboboxes which will provide details for the user about cbo_Event1 on the search form. All four comboboxes are linked to other tables for lookup values.

I've made bound (cbo_Event1) and unbound (cmb_Event) versions of the combobox. I've also used Me.cbo_Event1.Value, Me.cbo_Event1.ListIndex, and Me.cbo_Event1 in the code.

Private Sub cbo_Event1_AfterUpdate()
   MsgBox ("Me.cbo_Event1 = " & Me.cbo_Event1 & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cbo_Event1_Change()
   MsgBox ("Me.cbo_Event1 = " & Me.cbo_Event1 & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cbo_Event1_Click()
   MsgBox ("Me.cbo_Event1 = " & Me.cbo_Event1 & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cmb_Event_AfterUpdate()
   MsgBox ("Me.cmb_Event = " & Me.cmb_Event & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cmb_Event_BeforeUpdate(Cancel As Integer)
   MsgBox ("Me.cmb_Event = " & Me.cmb_Event & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cmb_Event_Change()
   MsgBox ("Me.cmb_Event = " & Me.cmb_Event & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

Private Sub cmb_Event_Click()
   MsgBox ("Me.cmb_Event = " & Me.cmb_Event & ".")
   If Me.cmb_Event = 0 Then
      Me.cmb_StartOfSeason = 0
      Me.cmb_EndOfSeason = 0
      Me.cmb_MoneyRequired = 0
   End If
End Sub

I get the same result across the board: the Event combobox does not detect that no selection was made when its drop-down list appears. The MsgBox function doesn't even trigger, indicating the event doesn't take place. I'm baffled as to why.

Answer 1

The only time I ever seen event handlers not firing like this is when writing (or pasting) an event handler doesn't actually link it to the appropriate event property and it is not listed in the event property sheet.

If you create the Sub statement by selecting the handler from the drop-down it will add it to the property sheet, or it can be added manually.

I presume you've also tried setting a breakpoint on the first statement of the handlers. If it doesn't hit it, then the handler is not linked to the control.