问题
Is there any way to not only be notified of a ScrollViewer's scroll, but to be able to prevent it. Something like a ScrollChanging event so I can set e.Cancel to true?
(I don't want to disable scrolling, nor do I want to implement it myself because it seems impossible to get the ScrollBar's events to detect a user dragging them. At least in UWP.)
The problem is that ScrollViewer_PointerWheelChanged isn't raised when it scrolls. Only when it doesn't have any need to scroll does it fire.
来源：https://stackoverflow.com/questions/33303617/prevent-a-scrollviewers-scrolling-conditionally