Flex中的Filter与Sort用法

<?xml version="1.0"?>
<!-- dpcontrols\SortFilterArrayCollection.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" width="600">
    <mx:Script>
        <![CDATA[
            import mx.collections.*;
    
            /* Function to sort the ICollectionView
               in ascending order. */
            public function sortAC():void {
                var sortA:Sort = new Sort();
                sortA.fields=[new SortField("label")];
                myAC.sort=sortA;
                //Refresh the collection view to show the sort.
                myAC.refresh();
            }

            /* Function to filter out all items with labels
               that are not in the range of M-N. */
            public function stateFilterFunc(item:Object):Boolean {
                return item.label >= "M" && item.label < "O";
            }
            
            /* Function to apply the filter function the ICollectionView. */
            public function filterAC():void {
                myAC.filterFunction=stateFilterFunc;
                /* Refresh the collection view to apply the filter. */
                myAC.refresh();
            }

            /* Function to Reset the view to its original state. */
            public function resetAC():void {
                myAC.filterFunction=null;
                myAC.sort=null;
                //Refresh the collection view.
                myAC.refresh();
            }

        ]]>
    </mx:Script>

    <!-- An ArrayCollection with an array of objects. -->
    <mx:ArrayCollection id="myAC">
        <mx:Array id="myArray">
            <mx:Object label="LA" data="Baton Rouge"/>
            <mx:Object label="NH" data="Concord"/>
            <mx:Object label="TX" data="Austin"/>
            <mx:Object label="MA" data="Boston"/>
            <mx:Object label="AZ" data="Phoenix"/>
            <mx:Object label="OR" data="Salem"/>
            <mx:Object label="FL" data="Tallahassee"/>
            <mx:Object label="MN" data="Saint Paul"/>
            <mx:Object label="NY" data="Albany"/>
        </mx:Array> 
    </mx:ArrayCollection>

    <!-- Buttons to filter, sort, or reset the view in the second ComboBox
            control. -->
    <mx:HBox width="100%">
        <mx:Button id="sortButton" label="Sort" click="sortAC();"/>
        <mx:Button id="filterButton" label="Filter" click="filterAC();"/>
        <mx:Button id="resetButton" label="Reset" click="resetAC();"/>
    </mx:HBox>
    <mx:VBox width="550" height="143" borderStyle="solid" paddingTop="10" paddingLeft="10">
        <mx:Label text="This box retains original order and contents of the Array:"/>
        <!-- A ComboBox populated by the underlying Array object.
            This control shows that Array retains its original order. -->
        <mx:ComboBox id="cb2" rowCount="10" dataProvider="{myArray}"/>
        <mx:HRule/>
        <mx:Label text="This box reflects the changes to the Array:"/>
        <!-- A ComboBox populated by the collection view of the Array. -->
        <mx:ComboBox id="cb1" rowCount="10" dataProvider="{myAC}"/>
    </mx:VBox>
</mx:Application>