Based on discussion http://wpftoolkit.codeplex.com/discussions/447813#post1069463
DecimalUpDown seems to be ignoring MouseWheelActiveOnFocus property. The mousewheel is only active when the mouse pointer is on the control irrespective of this setting.
"MouseWheelActiveOnFocus" property is now obsolete, but the same problem occurs with "MouseWheelActiveTrigger" property :
When focus is on the DecimalUpDown (with MouseWheelActiveTrigger = Focused), and mouse pointer is outside the DecimalUpDown, using the mouseWheel does nothing. If the mouse pointer is over the DecimalUpDown, using the mouseWheel increments/decrements.
It looks like ButtonSpinner.OnMouseWheel() is only called when mouse is over the Control.
Comments: ** Comment from web user: dbcontext **
DecimalUpDown seems to be ignoring MouseWheelActiveOnFocus property. The mousewheel is only active when the mouse pointer is on the control irrespective of this setting.
"MouseWheelActiveOnFocus" property is now obsolete, but the same problem occurs with "MouseWheelActiveTrigger" property :
When focus is on the DecimalUpDown (with MouseWheelActiveTrigger = Focused), and mouse pointer is outside the DecimalUpDown, using the mouseWheel does nothing. If the mouse pointer is over the DecimalUpDown, using the mouseWheel increments/decrements.
It looks like ButtonSpinner.OnMouseWheel() is only called when mouse is over the Control.
Comments: ** Comment from web user: dbcontext **
So there is no way we can have Mouse Wheel to work without the mouse being over the control ?
This is how it worked in Windows Forms and the way I expect it to work. (At least add it as an option). I am using the numericUpDown in a DataGrid, so it usually receives focus via keyboard Tab. It's counterproductive to have to move mouse as well on top of NumericUpDown to be able to scroll control.
If you found difficulty imprelementing it due to limits of WPF it's another thing all together.