Visual Basic

Private Const WM_MOUSEWHEEL As Integer = &H20A<br />
<br />
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)<br />
        Select Case m.Msg<br />
            Case WM_MOUSEWHEEL<br />
                Select Case True<br />
                      Exit Sub<br />
        End Select<br />
        MyBase.WndProc(m)<br />
    End Sub

Public Class MyComboBox
    Inherits ComboBox
 
    Private Const WM_MOUSEWHEEL As Integer = &H20A
 
    Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
        Select Case m.Msg
            Case WM_MOUSEWHEEL
                ' If we see a MouseWheel message, do not process it!
                Exit Sub
        End Select
 
        ' All other messages get processed as normal.
        MyBase.WndProc(m)
    End Sub
End Class