Adding OnChange event to dynamically created vba form controls - vba

Question

I have a form in excel, where I need to have dynamically created Comboboxes and Listboxes. So, the idea is, each listbox is linked to combobox. The first ones are set up by default, and user can press the "Add" button, if he needs to add another combo + list boxes. So the code for "Add" button is following:
Private Sub AddCountry_Click()
aaa = "a"
Set comb = Controls.Add("Forms.Combobox.1", "CountryList" & Val(CountryLabel.Caption) + 1)
With comb
.Top = CountryList1.Top
.Width = CountryList1.Width
.Height = CountryList1.Height
.Left = (CountryList1.Width + 3) * Val(CountryLabel.Caption) + CountryList1.Left
.AddItem ("--Choose country--")
For i = 3 To 20
.AddItem Worksheets("Countries").Range("B" & i).Value
Next i
.Text = "--Choose country--"
End With
Set listb = Controls.Add("Forms.Listbox.1", "Countries" & Val(CountryLabel.Caption) + 1)
With listb
.Top = Countries1.Top
.Width = Countries1.Width
.Height = Countries1.Height
.Left = (Countries1.Width + 3) * Val(CountryLabel.Caption) + Countries1.Left
.ColumnCount = 2
.MultiSelect = 1
End With
CountryLabel.Caption = Val(CountryLabel.Caption) + 1
End Sub
The idea is, that Comboboxes must will have names "CountryList" and a number, that is stored in invisible label (to which is added +1 every time the button is bressed), so it will be CountryList1, CountryList2, etc. Same for listboxes.
So the thing is, that comboboxes are made and values (country names) are added correctly. But I did not get, how to use them after it? The thing, that I need is to - when a combobox is changed (user selects different country), the list box below must be filled with certain values (different for each country).
I assume, the problem might be in defining the name for combo/list box. So is it possible to add dynamical names (CountryList1, CountryList2, etc) and then somehow add OnChange Events? Thanks in advance.

Answer 1

Here's an example for the ComboBox. You can base the listbox of of it, since the principle is the exact same.
First create a class named cComboBox and put this code in there:
Private WithEvents p_ComboBoxEvents As MSForms.ComboBox
Private Sub p_ComboBoxEvents_Change()
'Here you can handle the events.
End Sub
Public Property Let Box(value As MSForms.ComboBox)
Set p_ComboBoxEvents = value
End Property
Public Property Get Box() As MSForms.ComboBox
Set Box= p_ComboBoxEvents
End Property
Next, in your existing code, you can add this cComboBox and just put the Combobox you're adding already:
'Add the custom box!
Private customBox as cComboBox
Private Sub AddCountry_Click()
aaa = "a"
Set comb = Controls.Add("Forms.Combobox.1", "CountryList" & Val(CountryLabel.Caption) + 1)
With comb
.Top = CountryList1.Top
.Width = CountryList1.Width
.Height = CountryList1.Height
.Left = (CountryList1.Width + 3) * Val(CountryLabel.Caption) + CountryList1.Left
.AddItem ("--Choose country--")
For i = 3 To 20
.AddItem Worksheets("Countries").Range("B" & i).Value
Next i
.Text = "--Choose country--"
End With
Set customBox = New cComboBox
customBox.Box = comb
End Sub
Of course you might want to create an array of these so you can have as many as you want, regardless of how they're named. However: you'll see that if you change the added ComboBox value the p_ComboBoxEvents_Change will trigger.