Using Excel VBA commands with variables - vba

Question

I'm trying reuse some code and thus make controlls in call a function to get different results. The problem seem to be to get references to the different controlls I want to update.
Function populate(num1, num2)
Dim index As Integer
index = ComboBox1.ListIndex
ComboBox2.Clear
Select Case index
Case Is = 0
With ComboBox2
ComboBox2.List = Worksheets("Sheet1").Range("A1:A10").Value
End With
Case Is = 1
With ComboBox2
ComboBox2.List = Worksheets("Sheet2").Range("A1:A10").Value
End With
Case Is = 2
With ComboBox2
ComboBox2.List = Worksheets("Sheet3").Range("A1:A10").Value
End With
End Select
End Function
Private Sub ComboBox1_Change()
Call populate(1, 2)
End Sub
Private Sub ComboBox3_Change()
Call populate(3, 4)
End Sub
Private Sub ComboBox5_Change()
Call populate(5, 6)
End Sub
Naturally, for every combobox I call ( odd numbers ), it should update the values of the 2nd combobox ( even numbers ). But instead of copying the code to each and every odd numbered combobox, I
d like to have some sort of code that actually gets reused by function calls as shown above.
Unfortunatly, I'm unsure of how to make that work in VBA. Needless to say, I'd like it to be something like ( which does not work ) :
Function populate(num1, num2)
Dim index As Integer
index = ComboBox + num1 + .ListIndex
ComboBox + num1 + .Clear
Select Case index
Case Is = 0
With ComboBox + num2
ComboBox + num2 + .List = Worksheets("Sheet1").Range("A1:A10").Value
End With
Case Is = 1
With ComboBox + num2
ComboBox + num2 + .List = Worksheets("Sheet2").Range("A1:A10").Value
End With
Case Is = 2
With ComboBox + num2
ComboBox + num2 + .List = Worksheets("Sheet3").Range("A1:A10").Value
End With
End Select
End Function
Also had a look at the possible duplicated question, tough that did not solve my problem. In fact, even if the subject seems dupicate, I don't think the question is. I'm trying to combine a partial command and a variable in order to create the command I want to use, whilst the possible duplicate seems to want something slightly different ... I might be wrong, but that's what it seemed like to me.

Answer 1

Instead of passing a number to your populate subroutine, pass the ComboBoxes that you wish to process:
Sub populate(cb1 As ComboBox, cb2 As ComboBox)
Dim index As Integer
index = cb1.ListIndex
With cb2
.Clear
Select Case index
Case 0
.List = Worksheets("Sheet1").Range("A1:A10").Value
Case 1
.List = Worksheets("Sheet2").Range("A1:A10").Value
Case 2
.List = Worksheets("Sheet3").Range("A1:A10").Value
End Select
End With
End Sub
Private Sub ComboBox1_Change()
populate ComboBox1, ComboBox2
End Sub
Private Sub ComboBox3_Change()
populate ComboBox3, ComboBox4
End Sub
Private Sub ComboBox5_Change()
populate ComboBox5, ComboBox6
End Sub

Answer 2

You can reference your comboboxes and other controls using the Sheet.Drawingobjects collection, as:
ActiveSheet.DrawingObjects("ComboBox" & num2)

Answer 3

Assuming you have userform comboboxes then your code can shorten down to:
Option Explicit
Sub populate(num1, num2)
Dim shtName As String
shtName = "Sheet" & (Me.Controls("Combobox" & num1).ListIndex + 1)
With Me.Controls("Combobox" & num2)
.Clear
.List = Worksheets(shtName).Range("A1:A10").Value
End With
End Sub
Otherwise, if you have ActiveX Excel comboboxes then it slightly changes to:
Option Explicit
Sub populate(num1, num2)
Dim shtName As String
shtName = "Sheet" & (ActiveSheet.DrawingObjects("ComboBox" & num1).Object.ListIndex + 1)
With ActiveSheet.DrawingObjects("Combobox" & num2).Object
.Clear
.List = Worksheets(shtName).Range("A1:A10").Value
End With
End Sub