带延时加载，自动刷新和拖动控制的Canvas

  Canvas应该是大家在开发flex接触比较多控件吧，但是它的功能比较单一，很多人都要给予2次开发，我也是一样，为了做好延时的flex控件异步加载。一个巨大的flex整体切割成为很多很小很小的swf，就要做了一个延时加载。每个Canvas都有。

1. <?xml version="1.0" encoding="utf-8"?>  
2. <mx:Canvas xmlns:mx="http://www.adobe.com/2006/mxml"  
3.            initialize="loadInit()"  
4.            backgroundColor="0xffffff">  
5.     <mx:Script>  
6.         <!--[CDATA[  
7.             import mx.controls.Image;  
8.             import mx.controls.Alert;  
9.   
10.             import flash.utils.setTimeout;  
11.   
12.             import org.bytearray.gif.player.GIFPlayer;  
13.   
14.             //自动刷新   
15.             public var autoRefreshPolicy="off";  
16.             public var autoRefreshTime:String="60000";  
17.             public var autoRefreshMethod:Function;  
18.   
19.             private var loading:Image;  
20.             private var myGIFPlayer:GIFPlayer=new GIFPlayer(true);  
21.   
22.             public var gifUrl:String="resource/image/config/canvasLoading.gif";  
23.   
24.             //移动性   
25.             private var oldIndex:int=0;  
26.             public var moveable:Boolean=false;  
27.   
28.             public function loadInit():void  
29.             {  
30.                 loading=new Image;  
31.                 loading.width=50;  
32.                 loading.height=50;  
33.                 loading.x=0;  
34.                 loading.y=0;  
35.   
36.                 var request:URLRequest=new URLRequest(gifUrl);  
37.                 myGIFPlayer.load(request);  
38.                 myGIFPlayer.visible=true;  
39.   
40.                 loading.addChild(myGIFPlayer);  
41.                 this.addChild(loading);  
42.                 this.enabled=false;  
43.   
44.                 if (autoRefreshPolicy == "on")  
45.                 {  
46.                     setTimeout(autoRefresh, 800);  
47.                 }  
48.   
49.                 this.addEventListener(flash.events.MouseEvent.MOUSE_DOWN, dragBegin);  
50.                 this.addEventListener(flash.events.MouseEvent.MOUSE_UP, dragEnd);  
51.             }  
52.   
53.             public function autoRefresh():void  
54.             {  
55.                 var time:Number=Number(autoRefreshTime) * 1000;  
56.                 var timer:Timer=new Timer(time);  
57.                 timer.addEventListener(TimerEvent.TIMER, onTimer);  
58.                 timer.start();  
59.             }  
60.   
61.   
62.             public function onTimer(event:TimerEvent):void  
63.             {  
64.                 if (autoRefreshMethod != null)  
65.                 {  
66.                     autoRefreshMethod.call(this);  
67.                 }  
68.                 else  
69.                 {  
70.                     Alert.show("自动刷新函数为空");  
71.                 }  
72.             }  
73.   
74.   
75.             public function startLoading():void  
76.             {  
77.                 loading.visible=true;  
78.                 this.enabled=false;  
79.             }  
80.   
81.             public function completeLoading():void  
82.             {  
83.                 loading.visible=false;  
84.                 this.enabled=true;  
85.             }  
86.   
87.             private function dragBegin(event:MouseEvent):void  
88.             {  
89.                 if (moveable == true)  
90.                 {  
91.                     oldIndex=this.parent.getChildIndex(this);  
92.                     this.parent.setChildIndex(this, this.parent.numChildren - 1);  
93.                     this.startDrag(false);  
94.                 }  
95.             }  
96.   
97.             private function dragEnd(event:MouseEvent):void  
98.             {  
99.                 if (moveable == true)  
100.                 {  
101.                     this.parent.setChildIndex(this, oldIndex);  
102.                     this.stopDrag();  
103.                 }  
104.             }  
105.   
106.             //延迟执行   
107.             protected function delayFunction(closure:Function, delay:Number, ... arguments):void  
108.             {  
109.                 setTimeout(closure, delay, arguments);  
110.             }  
111.         ]]-->  
112.     </mx:Script>  
113. </mx:Canvas>