Hi Erik,
There isn't an event for this, but you can create one by overriding the "_adjust" function that will raise an event before calling the original _adjust function.
If I have a numericTextBox defined as follows:
I could override the "_adjust" function and raise an event like this:
Then I can subscribe to the event like this:
Attached is a working example.
Hope this helps.
Regards,
John DeVight