<? xml?version = " 1.0 " ?encoding = " utf-8 " ?>
< mx:Application?xmlns:mx = " http://www.adobe.com/2006/mxml "
????????????????layout = " vertical "
????????????????creationComplete = " initApp() " >

< mx:Script >
<! [CDATA[

???? // ?On?startup
???? public ?function?initApp(): void
????{
???????? // ?Set?filter?function
???????? // ?Be?careful?to?set?filterFunction
???????? // ?only?after?ArrayCollection?has?been
???????? // ?populated.
????????myData.filterFunction = processFilter;
????}

???? // ?Filter?function
???? public ?function?processFilter(item:Object):Boolean
????{
????????var?result:Boolean = false ;

???????? // ?If?no?filter?text,?or?a?match,?then?true
???????? if ?( ! item.name.length
???????????????? || ?item.name.toUpperCase().indexOf(txtFilter.text.toUpperCase())? >= ? 0 )
????????result = true ;

???????? return ?result;
????}
]] >
</ mx:Script >

<!-- ?Data?(use?ArrayCollection)? -->
< mx:ArrayCollection?id = " myData " >
???? < mx:source >
???????? < mx:Object?name = " Ben?Forta "
????????????location = " Oak?Park,?MI "
????????????phone = " (248)555-5555 " ? />
???????? < mx:Object?name = " Jane?Doe "
????????????location = " New?York,?NY "
????????????phone = " (212)555-1234 " ? />
???????? < mx:Object?name = " Jim?Jones "
????????????location = " Atlanta,?GA "
????????????phone = " (414)555-1212 " ? />
???????? < mx:Object?name = " Roberta?Roberts "
????????????location = " Chicago,?IL "
????????????phone = " (312)555-4321 " ? />
???????? < mx:Object?name = " Steve?Stevens "
????????????location = " Boston,?MA "
????????????phone = " (617)555-5656 " ? />
???? </ mx:source >
</ mx:ArrayCollection >

<!-- ?UI? -->
< mx:HBox?width = " 100% " >
???? < mx:Label?text = " Filter: " />
???? < mx:TextInput?id = " txtFilter "
????????????width = " 100% "
????????????change = " myData.refresh() " />
</ mx:HBox >

< mx:DataGrid?dataProvider = " {myData} "
????????width = " 100% " ?height = " 100% " >
???? < mx:columns >
???????? < mx:DataGridColumn?headerText = " Name "
????????????????????dataField = " name " />
???????? < mx:DataGridColumn?headerText = " Location "
????????????????????dataField = " location " />
???????? < mx:DataGridColumn?headerText = " Phone " ????????????dataField = " phone " />
???? </ mx:columns >
</ mx:DataGrid >
</ mx:Application >

其中主要的是ArrayCollection的filterFunction屬性,他的使用方法如下:
ArrayCollection的filterFunction屬性是繼承自ListCollectionView的，還有其他類具有這個功能,以下是一個繼承關系圖,詳細的可以看flex 的幫助文件
filterFunction屬性的值是一個函數(Function)：
參數：Object類型的一個值,也可以不帶參數；
返回值：Boolean類型的值，如果返回值為True就把這個Object放到里面,反之亦然。
其函數格式事例如下：
f(item:Object):Boolean
在函數里面進行處理,以上的例子就是如此：
?public function processFilter(item:Object):Boolean
?{
?????? var result:Boolean=false;
????? //?查看文本框里的字符串長度或字符串的匹配（大小寫都可以），然后返回結果。
??????if (!item.name.length || item.name.toUpperCase().indexOf(txtFilter.text.toUpperCase()) >= 0)
??? ?result=true;
??? ?return result;
?}
注意：filterFunction函數只有在對象建立的時候和調用reflash()的時候執行的，所以一定要在顯示之前調用下reflash()，否則顯示就不正常了，切記！切記！