FLEX例子之下拉列表框(ComboBox)

<?xml version="1.0"?>
<!-- Simple example to demonstrate the ComboBox control. -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundGradientColors="[0x000000,0x323232]" viewSourceURL="srcview/index.html">
<!--这个例子实现的是一个ComboBox下拉列表框,列表的选项是由绑定数组为数据源的.当关闭(选择)列表时,被选中的值进行了传递,又由closeHandler函数对label进行了赋值(修改)-->
    <mx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
 
            [Bindable]
            public var cards:ArrayCollection = new ArrayCollection(
                [ {label:"Visa",data:1}, //这样的数组分配方式也是第一次见:) 经过分析才学习到:这里的"data"似乎是自定义的变量名,label是组件"label"
                  {label:"MasterCard", data:2}, 
                  {label:"American Express", data:3} ]);
 
            private function closeHandler(event:Event):void {
                myLabel.text = "You selected: " +  ComboBox(event.target).selectedItem.label;//targht是event事件的目标;ComboBox具有selectedItem属性
                myData.text = "Data: " +  ComboBox(event.target).selectedItem.data;
            }     
        ]]>
    </mx:Script>
 
    <mx:Panel title="ComboBox Control Example" 
        height="75%" width="75%" layout="horizontal"
        paddingTop="10" paddingBottom="10" paddingLeft="10" paddingRight="10"
        color="0xffffff" borderAlpha="0.15">
 
        <mx:ComboBox dataProvider="{cards}" width="150" color="0x000000"
            close="closeHandler(event);"/>
 
        <mx:VBox width="250" color="0x000000">
            <mx:Text  width="200" color="blue" text="Select a type of credit card."/>
            <mx:Label id="myLabel" text="You selected:"/>
            <mx:Label id="myData" text="Data:"/>
        </mx:VBox>         
 
    </mx:Panel>    
</mx:Application>