Flex4 Spark 组件生命周期

Flex组件生命周期存在三个阶段：1、诞生；2、生存；3、死亡。

事件顺序 preinitialize，initialize，creationComplete

<?xml version="1.0" encoding="utf-8"?>
<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"
  preinitialize="onPreinitialize(event)"
  initialize="onInitialize(event)"
  creationComplete="onCreationComplete(event)"
  elementAdd="onElementAdd(event)"
  elementRemove="onElementRemove(event)"
  applicationComplete="onApplicationComplete(event)"
  width="100%" height="100%">
	<!--上述相应时间的方法均采用 on某时间 的命名规则-->
<fx:Script><![CDATA[
  import spark.events.ElementExistenceEvent;
  import mx.events.FlexEvent;
  
  [Bindable]
  private var _text:String = "";
  
  protected function onPreinitialize(event:FlexEvent):void {
    _text += "onPreinitialize: " + event + "n";
  }

  protected function onInitialize(event:FlexEvent):void {
    _text += "onInitialize: " + event + "n";
  }

  protected function onCreationComplete(event:FlexEvent):void {
    _text += "onCreationComplete: " + event + "n";
  }

  protected function onApplicationComplete(
  event:FlexEvent):void {
    _text += "onApplicationComplete: " + event + "n";
  }

  protected function onElementAdd(event:ElementExistenceEvent):
  void {
    _text += "onElementAdd: " + event + ",target = " +
      event.element + "n";
  }
  protected function onElementRemove(
  event:ElementExistenceEvent):void {
    _text += "onElementRemove: " + event + "n";
  }
]]></fx:Script>
  <s:layout>
    <s:VerticalLayout paddingLeft="10" paddingTop="10"
      paddingRight="10" paddingBottom="10"/>
  </s:layout>
  <s:Button id="kenny" label="移除按钮!"
    click="removeElement(kenny)"/>
  <s:TextArea id="debugTA" text="{_text}" width="100%"
    height="100%"/>
</s:Application>