The entity name must immediately follow the '&' in the entity reference.
在flex中出现上述错误,是因为不识别&标识符,需要将:
<mx:TextInput text="{(_feed.url && !_feed.isTemporary)?_feed.url:'Save Feed to generate URL'}"
<mx:TextInput text="{(_feed.url && !_feed.isTemporary)?_feed.url:'Save Feed to generate URL'}" /