3.15.使用延迟实例化提高启动效率

<mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml" height="600"
width="600">
<mx:Script>
<![CDATA[
private function changeViewStackCreation():void
{
viewStack.creationPolicy = (comboBox.selectedItem as
String);
viewStack.createComponentsFromDescriptors(true);
}
private function changeViewStack():void
{
viewStack.selectedIndex =
comboBoxChangeIndex.selectedIndex;
}

]]>
</mx:Script>
<mx:Fade alphaFrom="0" alphaTo="1" duration="4000"
id="fadeIn"/>
<mx:ComboBox dataProvider="{['none', 'all', 'queued',
'auto']}" change="changeViewStackCreation()"
id="comboBox"/>
<mx:ComboBox dataProvider="{[1, 2, 3, 4]}" x="150"
change="changeViewStack()" id="comboBoxChangeIndex"/>
<mx:ViewStack id="viewStack" width="400" height="300"
creationPolicy="none" y="100">
<mx:Canvas creationCompleteEffect="{fadeIn}"
creationIndex="0" backgroundColor="#0000ff"
id="canvas1">
<mx:LinkButton label="Link Button Number One"/>
</mx:Canvas>
<mx:Canvas creationCompleteEffect="{fadeIn}"
creationIndex="1" backgroundColor="#0000ff"
id="canvas2">
<mx:LinkButton label="Link Button Number Two"/>
</mx:Canvas>
<mx:Canvas creationIndex="2" id="canvas3"
creationCompleteEffect="{fadeIn}" backgroundColor="#0000ff">
<mx:LinkButton label="Link Button Number Three"/>
</mx:Canvas>
<mx:Canvas creationIndex="3" id="canvas4"
creationCompleteEffect="{fadeIn}" backgroundColor="#0000ff" >
<mx:LinkButton label="Link Button Number Four"/>
</mx:Canvas>
</mx:ViewStack>
</mx:Canvas>