Originariamente inviato da Fado84
non funge..
Hai dichiarato la SendMessage, come tu stesso hai scritto ?
codice:
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 Sub Command1_Click()
Const WM_USER = &H400
Const CB_SHOWDROPDOWN = (WM_USER + 15)
SendMessage Combo1.hwnd, CB_SHOWDROPDOWN, 1, 0&
' Per aprire
SendMessage Combo1.hwnd, CB_SHOWDROPDOWN, 1, 0&
' Per chiudere
End Sub