How to populate a combobox using an arraylist? - excel

Question

I am trying to populate a combo box using an arraylist. I used the following code but it doesn't seem to work.
Private Sub UserForm_Initialize()
Sheets("MSS").Select
Dim counter As Integer
Dim cmbox_opt As String
Dim array_cmbox As ArrayList
Set array_cmbox = New ArrayList
Dim last_row As Integer
Dim i As Integer
last_row = Range("B" & Rows.Count).End(xlUp).Row
For counter = 3 To last_row
cmbox_opt = Range("B" & counter).Value
If Not array_cmbox.Contains(cmbox_opt) Then
array_cmbox.Add cmbox_opt
End If
Next
For i = 1 To i = 1 + i
If array_cmbox.Contains(array_cmbox(i)) Then
Me.ComboBoxArea.AddItem array_cmbox(i)
End If
Next
'Ensure Window Dimensions'
With Me
.Width = 577
.Caption = "Master Sanitation Schedule Form v.1.0"
.Height = 274
End With
End Sub
However, if I just add the line
Me.ComboBoxArea.AddItem array_cmbox(2)
It does add the second item to the combo box from the ArrayList

Answer 1

Populate a Combo Box Using an Array List
Private Sub UserForm_Initialize()
PopulateComboBoxArea
'Ensure Window Dimensions'
With Me
.Width = 577
.Caption = "Master Sanitation Schedule Form v.1.0"
.Height = 274
End With
End Sub
Private Sub PopulateComboBoxArea()
' Define constants.
Const wsName As String = "MSS"
Const FirstRow As Long = 3
Const Col As String = "B"
' Reference the workbook ('wb').
Dim wb As Workbook: Set wb = ThisWorkbook ' workbook containing this code
' Reference the worksheet ('ws').
Dim ws As Worksheet: Set ws = wb.Worksheets(wsName)
' Calculate the last row ('LastRow'),
' the row of the last non-empty cell in the column.
Dim LastRow As Long: LastRow = ws.Cells(ws.Rows.Count, Col).End(xlUp).Row
' Validate the last row.
If FirstRow > LastRow Then Exit Sub
' Reference the one-column range ('crg').
Dim crg As Range
Set crg = ws.Range(ws.Cells(FirstRow, Col), ws.Cells(LastRow, Col))
' Write the number of rows to a variable ('rCount').
Dim rCount As Long: rCount = crg.Rows.Count
' Write the values from the (one-column) range
' to a 2D one-based (one-column) array ('cData').
Dim cData() As Variant
If rCount = 1 Then ' one cell
ReDim cData(1 To 1, 1 To 1): cData(1, 1) = crg.Value
Else ' multiple cells
cData = crg.Value
End If
' Create and reference a new array list.
' Either early binding: needs a reference to 'mscorlib.dll'...
'Dim arl As ArrayList: Set arl = New ArrayList
' ... or late binding: no reference needed
Dim arl As Object: Set arl = CreateObject("System.Collections.ArrayList")
' IMO, this would be the way to go since when using early binding,
' the Intellisense, that would be useful to easily learn how to use
' the array list, doesn't work at this moment.
' Declare additional variables.
Dim r As Long ' Current Array Row
Dim cString As String ' Current Array Value Converted to a String
' Loop through the rows of the array...
For r = 1 To rCount
' Write the value converted to a string to a variable ('cString').
cString = CStr(cData(r, 1))
' Check if the string doesn't exist in the array list.
If Not arl.Contains(cString) Then ' string is not in the array list...
arl.Add cString ' ... so add it
'Else ' string is already in the array list; do nothing
End If
Next r
' IMO, a huge disadvantage, compared to the dictionary, is that
' you cannot compare the strings case-insensitively when using 'Contains'.
' When using a dictionary you could simply use
' e.g. dict.CompareMode = vbTextCompare' making e.g. 'A = a'.
' IMO, one of the very few reasons to use an array list over a dictionary
' is that you can easily sort it:
arl.Sort
' Populate the combo box with the values from the array list
' (no need to loop).
Me.ComboBoxArea.List = arl.ToArray
End Sub