poppedViewReturnedObject 仅在最初推送包含覆盖的 createReturnObject 方法的新视图的视图的 addHandler 中可用。
poppedViewReturnedObject 何时可用,即不为空?当然,当调用 popview() 时。
如果您尝试在其他情况下访问 poppedViewReturnedObject,例如在 viewActivated 处理程序中,它将为空。
代码示例:
<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
add="addHandler(event)"
viewActivate="viewActivateHandler(event)"
>
<fx:Script>
<![CDATA[
import mx.events.FlexEvent;
import spark.events.ViewNavigatorEvent;
protected function addHandler(event:FlexEvent):void
{
if (navigator.poppedViewReturnedObject==null){
// do something
var poppedViewReturnedObject:ViewReturnObject = navigator.poppedViewReturnedObject;
}
}
protected function viewActivateHandler(event:ViewNavigatorEvent):void
{
// here , navigator.poppedViewReturnedObject is null
}
]]>
</fx:Script>