Option Explicit
Dim b As Boolean
Private Sub ListBox1_MouseDown(ByVal Button As Integer, ByVal Shift As Integer, ByVal X As Single, ByVal Y As Single)
Dim v As Byte
v = 10 'pas de défilement
With ListBox1
.TopIndex = IIf(b = False, .TopIndex + v, IIf((.TopIndex - v) >= 0, .TopIndex - v, 0))
If (.TopIndex + v) > .ListCount Then
b = True
ElseIf (.TopIndex + v) <= v Then b = False
End If
End With
End Sub