Skip window from being captured

If I understood correctly your problem.

You can use built in Flex/as3 function to take a screenshot of the entire application or a particular component then convert into bytearray and PngEncoder (or JPGEncoder if you prefer), than save it…

Here’s an example:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                       xmlns:s="library://ns.adobe.com/flex/spark" 
                       xmlns:mx="library://ns.adobe.com/flex/mx">   
    <fx:Script>
        <![CDATA[
            import mx.graphics.codec.PNGEncoder;

            private function takeSnapshot(comp:DisplayObject):void {
                var bitmapData:BitmapData = new BitmapData(comp.width,comp.height,false,0x00000000);
                bitmapData.draw(comp, new Matrix());

                var fileStream:FileStream = new FileStream();
                fileStream.open(File.desktopDirectory.resolvePath("screenshot.png"), FileMode.UPDATE);
                fileStream.writeBytes(new PNGEncoder().encode(bitmapData));
            }
        ]]>
    </fx:Script>    
    <s:BorderContainer width="100%" height="100%" backgroundColor="#ff00ff">
        <s:Label text="this text and box should be saved"/>
        <s:BorderContainer width="25%" height="25%" backgroundColor="#ffff00" horizontalCenter="0"
                           id="extended"
                           verticalCenter="0">
            <s:Label text="this text and box should be saved" width="100%" maxDisplayedLines="5"/>
        </s:BorderContainer>
    </s:BorderContainer>    
    <s:Button bottom="0" left="0" label="screen" click="takeSnapshot(extended)"/>
</s:WindowedApplication>

EDIT:

As I thought I misunderstood the request..

The only way I can think of is to:

1. Minimize the application (this.minimize();) or setting the alpha to 0 (this.alpha=0).
2. Take the screenshot
3. Maximize the application (this.maximize();) or setting the alpha to 1 (this.alpha=0).