看看下面的代码。
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx" 
               xmlns:view="client.view.*" minWidth="955" minHeight="600">
    <s:Panel x="10" y="10" height="100%" title="CTW" borderColor="#008040" fontFamily="Arial" fontWeight="bold" fontSize="13">
        <s:HGroup>
            ...
            <s:Scroller id="canvasGroup" width="650" height="500">
                <s:Group>
                    <s:SpriteVisualElement>
                        <view:PNGCanvas id="canvas" />  <!-- error is thrown here -->
                    </s:SpriteVisualElement>
                </s:Group>
            </s:Scroller>
        </s:HGroup>
    </s:Panel>  
</s:Application>
PNGCanvas延伸flash.display.Sprite。我收到一个错误component declarations are not allowed here(在标有 的行上error is thrown here)。这里有什么问题?
先感谢您!!!