The name of the callback function, UserGroupList goes in the row source type under the data tab in the combobox. This example is reading the Users and Groups collections to show valid users/groups in the app.
In the example under Case acLBInitialize put your recordset and load the array. If you start out by only loading 2 columns the rest of the logic should work and you can expand from that point. The initialize is run once to build the array and from that point the data is extracted from the array to load the listbox.
Example of a callback function.
Function UserGroupList(fld As Control, ID As Variant, _
rowX As Variant, col As Variant, _
code As Variant) As Variant
Dim ur As ADOX.User, gp As ADOX.Group
Static myarray() As Variant
Static row As Integer, rowcount As Integer
Dim cg As New ADOX.Catalog
Dim ReturnVal As Variant
ReturnVal = Null
Select Case code
Case acLBInitialize ' Initialize.
Set cg.ActiveConnection = CurrentProject.Connection
rowcount = cg.Users.Count
row = 0
ReDim Preserve myarray(rowcount, 2)
For Each ur In cg.Users
myarray(row, 0) = ur.Name
For Each gp In ur.Groups
myarray(row, 1) = gp.Name
Next
row = row + 1
If row = rowcount Then Exit For
Next
ReturnVal = rowcount
Case acLBOpen ' Open.
' Generate unique ID for control.
ReturnVal = Timer
Case acLBGetRowCount ' Get number of rows.
ReturnVal = rowcount
Case acLBGetColumnCount ' Get number of columns.
ReturnVal = 2
Case acLBGetColumnWidth ' Column width.
' -1 forces use of default width.
ReturnVal = -1
Case acLBGetValue ' Get data.
'-- zero based array
'Select Case col
' Case 0
' ReturnVal = myarray(rowX, 0)
' Case 1
' ReturnVal = myarray(rowX, 1)
'End Select
ReturnVal = myarray(rowX, col)
Debug.Print "column = "; col
Case acLBEnd ' End.
Erase myarray
End Select
'''''Debug.Print "return value = "; ReturnVal
UserGroupList = ReturnVal
End Function
