Turn off mousewheel event.

[Qwert]

Hello,

when a NumericUpDown control has the focus, the mousewheel
increases/decreases its value. How does one prevent this from happening? How
does one turn off its mousewheel event?

Thanks.

[Larry Lard]

Re: Turn off mousewheel event.


Qwert wrote:[color=blue]
> Hello,
>
> when a NumericUpDown control has the focus, the mousewheel
> increases/decreases its value. How does one prevent this from happening? How
> does one turn off its mousewheel event?[/color]

Because a MouseEventArgs doesn't have a Cancel, we have to do a little
more work. This is one way, if there's a less fiddly way someone will
be along soon enough to tell you about it :)

What we do here is derive our own class from NumericUpDown, and
override the handling of the MouseWheel event. First define our class:

Friend Class MyNumericUpDown
Inherits NumericUpDown

Protected Overrides Sub OnMouseWheel(By Val e As MouseEventArgs)
'do nothing
End Sub

End Class

Note that the 'normal' behaviour of a method in a derived class is to
first do its base class's behavior, then do its own. Here we explicitly
do nothing when a mouse wheel event occurs.

Now you just need to use this new control instead of the regular
NumericUpDown. A quick way of doing this is to just place a normal
NumericUpDown on your form, then in the auto-generated code section,
change two things:

Change the declaration of the control from

Friend WithEvents NumericUpDown1 As NumericUpDown
to
Friend WithEvents NumericUpDown1 As MyNumericUpDown

and change the creation of the control (in InitializeCompo nent) from

Me.NumericUpDow n1 = New System.Windows. Forms.NumericUp Down
to
Me.NumericUpDow n1 = New MyNumericUpDown

Because a MyNumericUpDown is still a NumericUpDown, you are still able
to use the visual designer as normal.

As I said, I'm not sure if this is all the best way to do this, but it
works.

--
Larry Lard
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