Question

I’m building SL application for zooming and panning across the layout. Everything is working fine, except that when I zoom in using mouse wheel , after some zoom scrollbars start to use mouse wheel so after that I can scroll not zoom. I only can zoom again if I put scrollbars at the end or begining. How to prevent scrollviewer from using mouse wheel? I want that zoom only be operated by wheel. Thank you in advance!

Here is my code of MouseWheel method when I’m zooming content :

protected override void OnMouseWheel(MouseWheelEventArgs e) 
    { 
        base.OnMouseWheel(e);             

        if (e.Delta > 0) 
        { 
            this.aniScaleX.To += 0.2; 
            this.aniScaleY.To += 0.2; 

            this.sbScale.Begin(); 
        } 
        else if (e.Delta < 0 && (this.aniScaleX.To > 1 && this.aniScaleY.To > 1)) 
        { 
            this.aniScaleX.To -= 0.2; 
            this.aniScaleY.To -= 0.2; 

            this.sbScale.Begin(); 
        } 

        Sizer.Width = Board.ActualWidth * (double)this.aniScaleX.To; 
        Sizer.Height = Board.ActualHeight * (double)this.aniScaleY.To; 

Answer 1

The MouseWheel event is a bubbling
event. This means that if multiple
MouseWheel event handlers are
registered for a sequence of objects
connected by parent-child
relationships in the object tree, the
event is potentially received by each
object in that relationship. The
bubbling metaphor indicates that the
event starts at the source and works
its way up the object tree. For a
bubbling event, the sender available
to the event handler identifies the
object where the event is handled, not
necessarily the object that actually
received the input condition that
initiated the event. To get the object
that initiated the event, use the
OriginalSource value of the event
data. http://msdn.microsoft.com/en-us/library/system.windows.uielement.mousewheel(VS.95).aspx

In my case,ScrollViewer always received event before because he is on the top of the visual tree. So I just registered event handler in scrollviewer on mouse wheel event and always when It happens, I simply redirect him to my “original” mousewheel function which do zoom.

I hope so that this will help somebody who is “stuck” like me here. Thank you all on your answers and suggestions..