未触发 VBA ComboBox 更改事件

Question

I have this issue with the ComboBox Event Handler.

I managed to create (and fill with items) the Comboboxes I wanted, the code seems to work fine. But after the program has run, if I try to pick one general item inside one of the comboboxes, it seems like the _Change Method is not called --> I cannot handle change events.

Here is my class module (class name: "DB_ComboBox")

    Option Explicit

    Public WithEvents DB_ComboBoxEvents As MSForms.ComboBox
    Private DB_ComboBox_Line As Integer

    Private Sub DB_ComboBoxEvents_Change()
        MsgBox ("Line : " & DB_ComboBox_Line)
        'Here I want handle The comboboxes changes
        'But this routine is not called!

    End Sub

    Sub Box(CBox As MSForms.ComboBox)
        Set DB_ComboBoxEvents = CBox
    End Sub


    Public Property Let Line(value As Integer)
        DB_ComboBox_Line = value
    End Property

    Public Property Get Line() As Integer
        Line = DB_ComboBox_Line
    End Property

And here is my "Main module", in which I create the comboboxes and pass them to a Collection of "DB_ComboBox"

        Sub CreateComboBox(IncCBoxes)

        Dim curCombo As MSForms.ComboBox
        Dim rng As Range
        Dim tot_items As Integer
        Dim incAddItem As Integer
        Dim incAddItemBis As Integer
        Dim itemBaseArray() As String
        Dim TEMP_ComboBoxInst As New DB_ComboBox


        Set rng = ActiveSheet.Range("J" & IncCBoxes)

        Set curCombo = ActiveSheet.OLEObjects.Add(ClassType:="Forms.ComboBox.1", Link:=False, DisplayAsIcon:=False, Left:=rng.Left, Top:=rng.Top, Width:=rng.Width, Height:=rng.Height).Object



         'Add the items
        itemBaseArray = Split(Foglio7.Cells(IncCBoxes, DBColFileComboIndexErrori), ";")

        For incAddItem = 0 To UBound(itemBaseArray)

            Dim itemLastArray() As String
            itemLastArray = Split(itemBaseArray(incAddItem), ",")

            For incAddItemBis = 0 To UBound(itemLastArray)
                curCombo.AddItem (itemLastArray(incAddItemBis))
            Next

        Next


        TEMP_ComboBoxInst.Box curCombo
        TEMP_ComboBoxInst.Line = IncCBoxes
        customBoxColl.Add TEMP_ComboBoxInst


    End Sub

Can anyone please tell me what I'm missing?

Thank you very much

Answer 1

This looks like a timing-issue: Running this code in another open file will work. In same file it does not. Seperate the adding to your class from the adding of the OLEControl ie: use Application.ontime now

see code below:

Private customBoxColl As New Collection

Sub CreateComboBox(IncCBoxes As Long)

        Dim curCombo As MSForms.ComboBox
        Dim rng As Range
        Dim tot_items As Integer
        Dim incAddItem As Integer
        Dim incAddItemBis As Integer
        Dim itemBaseArray() As String
        Dim itemLastArray() As String

        Set rng = ActiveSheet.Range("J" & IncCBoxes)

        With ActiveSheet.OLEObjects.Add(ClassType:="Forms.ComboBox.1", Link:=False, DisplayAsIcon:=False, Left:=rng.Left, Top:=rng.Top, Width:=rng.Width, Height:=rng.Height)
            Set curCombo = .Object
        End With

         'Add the items
        itemBaseArray = Split(Foglio7.Cells(IncCBoxes, DBColFileComboIndexErrori), ";")
        For incAddItem = 0 To UBound(itemBaseArray)
            itemLastArray = Split(itemBaseArray(incAddItem), ",")
            For incAddItemBis = 0 To UBound(itemLastArray)
               curCombo.AddItem (itemLastArray(incAddItemBis))
            Next
        Next
    Application.OnTime Now, "'CallToClass """ & curCombo.Name & """,""" & IncCBoxes & "'"
End Sub

Sub CalltoClass(ctl As String, myline As Long)
Dim TEMP_ComboBoxInst As New DB_ComboBox
        TEMP_ComboBoxInst.Box ActiveSheet.OLEObjects(ctl).Object
        TEMP_ComboBoxInst.line = myline
        customBoxColl.Add TEMP_ComboBoxInst
End Sub

Answer 2

I know this doesn't apply to your specific problem, but I'll just post this here for any others who may have this problem. In my case, the events stopped firing because I had just copied my database into a new Github repo.

On reopening Access, the events weren't firing while they had been fine the day before, which completely stumped me, especially since none of the SO answers seemed to address my issue. Basically, Access blocks macros and code, and requires it to be reenabled by clicking OK on the little yellow warning at the top of the screen.