Option Explicit 
     
    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 Const LB_SETHORIZONTALEXTENT = &H194 
     
    Private Sub Command1_Click() 
     List1.AddItem "Line 1" 
     List1.AddItem "a big Line 2 some text some text" 
     List1.AddItem "Line 3" 
     addHorScrlBarListBox List1 
    End Sub 
     
    Public Sub addHorScrlBarListBox(ByVal refControlListBox As Object) 
     ' ¼Ó ºá Ïò ¹ö ¶¯ Ìõ 
     
     Dim nRet As Long 
     Dim nNewWidth As Integer 
     
     nNewWidth = refControlListBox.Width + 100 ' ÐÂ ¿í ¶È £¬ ÒÔ Ïñ ËØ Îª µ¥ Î» ¡£ 
     nRet = SendMessage(refControlListBox.hwnd, _ 
     LB_SETHORIZONTALEXTENT, nNewWidth, ByVal 0&) 
    End Sub 
<END>