Binaryworld - ListBoxItemFromPoint - The index of a ListBox item at given coordinate ... [ VB -> Controls-ListView ]

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
Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dest As _
  Any, dest As Any, ByVal numBytes As Long)
Const LB_ITEMFROMPOINT = &H1A9

' Return the index of a ListBox item at given coordinates
' X and Y are in pixels and relative to the ListBox's upperleft corner
'
' This is similar to the HitTest method of the ListView control
'
' Here an example that shows the index of the item under the cursor
' Private Sub List1_MouseMove(Button As Integer, Shift As Integer,
' '    X As Single, Y As Single)
'   Label1 = ListBoxItemFromPoint(List1, '   ScaleX(X, vbTwips, vbPixels),
' ScaleY(Y, vbTwips, vbPixels))
' End Sub

Function ListBoxItemFromPoint(lb As ListBox, ByVal X As Long, _
  ByVal Y As Long) As Long
  Dim lParam As Long

  ' lParam must contain X in its low-order word
  ' and Y in its high-order word.
  ' filling the low-order word is easy
  lParam = X
  ' We need this method to avoid overflow.
  CopyMemory ByVal VarPtr(lParam) + 2, Y, 2

  ListBoxItemFromPoint = SendMessage(lb.hwnd, LB_ITEMFROMPOINT, 0, _
    ByVal lParam)
End Function