Qwert said:
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?
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(ByVal 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 InitializeComponent) from
Me.NumericUpDown1 = New System.Windows.Forms.NumericUpDown
to
Me.NumericUpDown1 = 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.
