How Can I let the backgroundAlpha is 0 when it run tweeneffect?

[GoogleCodeExporter]

How Can I let the backgroundAlpha is 0  when it run tweeneffect?

What is the expected output? What do you see instead?
I found it use the ViewStack's backgroundColor,
But I want to backgroundAlpha is 0.

What version of the product are you using? 
  Efflex_v0.03_fx3_fp9.swc

Please provide any additional information below.

This is the simple code I use:

<mx:ViewStack id="viewStack"  width="700" height="300"
 backgroundAlpha="0" backgroundColor="#000000">
         <mx:Canvas showEffect="effect" hideEffect="effect"  
                     backgroundAlpha="0" backgroundColor="#241B1B">
                       <mx:TileList dataProvider="{kinds_xml.kind}" 
                                itemRenderer="MyItem"  
                        rowCount="2" columnCount="4"
                                width="100%" height="100%" 
                                backgroundAlpha="0" 
                                backgroundColor="#781212"/>
                </mx:Canvas>
                <mx:Canvas showEffect="effect" hideEffect="effect"  
                     backgroundAlpha="0" backgroundColor="#241B1B">
                       <mx:TileList dataProvider="{kinds_xml.kind}" 
                                itemRenderer="MyItem"  
                        rowCount="2" columnCount="4"
                                width="100%" height="100%" 
                                backgroundAlpha="0" 
                                backgroundColor="#222222"/>
                </mx:Canvas>
 </mx:ViewStack>

I set all UIComponent's backgroundAlpha="0"  ,but It is no use .
I think you use the viewStack.getStyle("backgroundColor") to draw snapshot.
Can you let the backgroundAlpha is used ? 

Original issue reported on code.google.com by gundamwo...@126.com on 21 Jul 2009 at 4:55

[GoogleCodeExporter]

I'm having the exact same issue. It's giving me a white background during the 
tween,
and I need the viewstack to remain with a zero alpha.

FlipPapervision3D effect
Efflex_v0.03_fx3_fp9.swc

Any help appreciated.

Original comment by willmor...@gmail.com on 30 Jul 2009 at 5:28

[GoogleCodeExporter]

FIXED! Sorry didn't see this before.

<viewStackEffects:FlipPapervision3D id="vsEffect" transparent="true" />

Original comment by willmor...@gmail.com on 30 Jul 2009 at 5:42

[GoogleCodeExporter]

OH! transparent="true" 
it's good ,thank you !

Original comment by gundamwo...@126.com on 6 Aug 2009 at 2:31

[GoogleCodeExporter]

transparent="true" it's ok! thank you very much;

Original comment by chaibing...@gmail.com on 21 Oct 2011 at 7:07