自定义Flex的Loading界面(源码)

package
{
??import flash.display.*;
??import flash.events.*;
??import flash.net.*;
??import flash.text.TextField;
??import flash.text.TextFormat;
??
??import mx.events.FlexEvent;
??import mx.preloaders.DownloadProgressBar;

??public class LoadingExampleProgressBar extends DownloadProgressBar
??{
????private var logo:Loader;
????private var txt:TextField;
????private var _preloader:Sprite;
????public function LoadingExampleProgressBar()
????{
??????logo = new Loader();
??????logo.load(new URLRequest("l4cd.png"));
??????addChild(logo);
??????
??????var style:TextFormat = new TextFormat(null,null,0xFFFFFF,"center");
??????txt = new TextField();
??????txt.defaultTextFormat = style;
??????txt.width = 200;
??????txt.selectable = false;
??????txt.height = 20;
??????addChild(txt);
??????
??????super();
????}
????//最重要的代码就在这里..重写preloader,让swf执行加载的时候~进行你希望的操作~
????override public function set preloader(value:Sprite):void{
??????_preloader = value
??????//四个侦听~分别是 加载进度 / 加载完毕 / 初始化进度 / 初始化完毕
??????_preloader.addEventListener(ProgressEvent.PROGRESS,load_progress);
??????_preloader.addEventListener(Event.COMPLETE,load_complete);
??????_preloader.addEventListener(FlexEvent.INIT_PROGRESS,init_progress);
??????_preloader.addEventListener(FlexEvent.INIT_COMPLETE,init_complete);
??????
??????stage.addEventListener(Event.RESIZE,resize)
??????resize(null);
????}
????private function remove():void{
??????_preloader.removeEventListener(ProgressEvent.PROGRESS,load_progress);
??????_preloader.removeEventListener(Event.COMPLETE,load_complete);
??????_preloader.removeEventListener(FlexEvent.INIT_PROGRESS,init_progress);
??????_preloader.removeEventListener(FlexEvent.INIT_COMPLETE,init_complete);
??????stage.removeEventListener(Event.RESIZE,resize)
????}
????private function resize(e:Event):void{
??????logo.x = (stage.stageWidth - 40)/2;
??????logo.y = (stage.stageHeight - 80)/2;
??????txt.x = (stage.stageWidth - 200)/2;
??????txt.y = logo.y + 40+5;
??????
??????graphics.clear();
??????graphics.beginFill(0x333333);
??????graphics.drawRect(0,stage.stageWidth,stage.stageHeight);
??????graphics.endFill();
????}
????private function load_progress(e:ProgressEvent):void{
??????txt.text = "正在加载..."+int(e.bytesLoaded/e.bytesTotal*100)+"%";
????}
????private function load_complete(e:Event):void{
??????txt.text = "加载完毕!"
????}
????private function init_progress(e:FlexEvent):void{
??????txt.text = "正在初始化..."
????}
????private function init_complete(e:FlexEvent):void{
??????txt.text = "初始化完毕!"
??????remove()
??????//最后这个地方需要dpe一个Event.COMPLETE事件..表示加载完毕让swf继续操作~
??????dispatchEvent(new Event(Event.COMPLETE))
????}
??}
}

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" ?
??preloader="LoadingExampleProgressBar" ?
??backgroundGradientAlphas="[1.0,1.0]" backgroundGradientColors="[#333333,#333333]"
</mx:Application>