???? ?網(wǎng)絡(luò)狀況是互聯(lián)網(wǎng)發(fā)展與軟件發(fā)展的一個(gè)很大的瓶頸，如果哪天訪問網(wǎng)上資源能象訪問本地硬盤，或者能象訪問內(nèi)存那樣快，那樣咱們的計(jì)算機(jī)以后只需要輸入輸出設(shè)備以及網(wǎng)絡(luò)設(shè)備就可以了，哈哈，這只是一個(gè)美好的愿望。

???? ?Flex應(yīng)用在Web開發(fā)上，避免不了網(wǎng)絡(luò)問題，下面的說明如何在加載數(shù)據(jù)時(shí)顯示Loading狀態(tài)，剛剛接觸Flex不久，歡迎拍磚。

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????? 原理是這樣的，首先定義了兩一個(gè)ViewState,其中一個(gè)就是Loading狀態(tài)，當(dāng)點(diǎn)擊按鈕的時(shí)候就顯示這個(gè)Loading視圖，直到數(shù)據(jù)加載完之顯示數(shù)據(jù)的視圖。?

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????? 先看效果圖片：

????? 首先，點(diǎn)擊了按鈕之后就會由于網(wǎng)絡(luò)問題顯示一個(gè)遮罩，上面用了一個(gè)Label顯示Loading...字樣，當(dāng)然這里可以用任何更加漂亮的東西替換，比如GIF的圖片。這里的網(wǎng)絡(luò)問題由于是在自己的機(jī)器上測試，是人為造成的，我的服務(wù)器代碼是使用的JAVA，在服務(wù)器上延遲了三秒加載數(shù)據(jù)。

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三秒之后顯示：

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代碼：

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    <?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
	<mx:states>
		<!--加載視圖,可以自己制作加載畫面，
		這個(gè)例子就只用了一個(gè)LABEL表示一下正在加載-->
		<!--數(shù)據(jù)加載成功后的State-->
		<mx:State name="ListState">
			<mx:AddChild relativeTo="{pl}" position="lastChild">
				<mx:Canvas id="can" width="100%" height="100%">
					<mx:DataGrid id="dg" horizontalCenter="0" width="100%" height="100%" >
						<mx:columns>
							<mx:DataGridColumn headerText="Id" dataField="p_id"/>
							<mx:DataGridColumn headerText="Title" dataField="p_title"/>
						</mx:columns>
					</mx:DataGrid>
				</mx:Canvas>
			</mx:AddChild>
		</mx:State>
		<!--加載狀態(tài)的視圖-->
		<mx:State name="LoadingState" basedOn="ListState">
			<mx:AddChild relativeTo="{can}" position="lastChild">
				<mx:Canvas id="shade" width="100%" height="100%"
					 backgroundColor="blue" backgroundAlpha="0.1">
					<mx:Label text="Loading..." horizontalCenter="0" verticalCenter="0" fontSize="14"/>
				</mx:Canvas>
			</mx:AddChild>
		</mx:State>
	</mx:states>
	<mx:Script>
		<![CDATA[
			import mx.rpc.AsyncToken;
			public function listLoad() {
				this.currentState = "LoadingState";
				//var loadListResponder:LoadListResponder = new LoadListResponder(this, this.dg);
				//var token:AsyncToken = listLoadService.send();
				//token.addResponder(loadListResponder);
				listLoadService.send();
			}
		]]>
	</mx:Script>
	<mx:HTTPService id="listLoadService"
					url="http://...."
					method="post">
					<mx:result>
						<![CDATA[
							this.dg.dataProvider = listLoadService.lastResult.data.problems.problem;
							this.currentState = "ListState";
						]]>
					</mx:result>
	</mx:HTTPService>
	<mx:Panel id="pl" title="lOAding..." width="400" height="300">
		
	</mx:Panel> 
	<mx:Button x="10" y="333" label="Load Data" click="listLoad()"/>
</mx:Application>

  

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參考文章：

?Show Flex Datagrid as busy while loading and reloading

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問題:

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I am using showbusycursor on my HTTPService so that while the datagid is loading is that the? cursor at least changes but I would like to do more like graying out the datagrid or something. ?But I am not sure where to start I tried:

?????? ?????<mx:DataGrid dataProvider="{repRoleUsersXLC}" width="100%" height="90%"
?????? ??????????? ?????? ? ? ? ? ? ? ? ?id="AssUsersDG"
?????? ??????????? ?????? ? ? ? ? ? ? ? ?updateComplete="this.enabled=true"
?????? ??????????? ?????? ? ? ? ? ? ? ? ?creationComplete="this.enabled=false"/>

but it didn't do as expected it disabled the scroll bar but I hoped it would disable grid. ?But I would like to do something that is really clear the data grid is loading and reloading thanks for any help.

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回答：

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Flex中在DataGrid加載數(shù)據(jù)時(shí)顯示Loading...