Binaryworld - GetListBoxSelectRange - Retrieve the index of all the selected items i ... [ VB -> Forms & Controls ]

Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal _
  hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
  lParam As Any) As Long
Const LB_GETSELITEMS = &H191

' Return an array with the indexes of all the selected items in a ListBox
' control
'
' the array is zero-based, but the significant values
' are from index 1 onward
' This is how you can use this routine
' Dim i As Long
' Dim indexes() As Long
' indexes() = GetListBoxSelectRange(List1)
' For i = 1 To UBound(indexes)
'    Debug.Print "Selected " & indexes(i)
' Next

Function GetListBoxSelectRange(lb As ListBox) As Long()
  Dim selCount As Long

  ' Retrieve the number of selected items (same as SelCount property)
  selCount = SendMessage(lb.hwnd, LB_GETSELCOUNT, 0, ByVal 0&)
  ' prepare the result array
  ReDim result(0 To selCount) As Long

  ' read all the indexes in one operation
  If selCount > 0 Then
    SendMessage lb.hwnd, LB_GETSELITEMS, selCount, result(1)
  End If
  ' return the array
  GetListBoxSelectRange = result()
End Function