如何使用Flex PopUpButton

<?xml version="1.0"?>
<!-- Simple example to demonstrate the PopUpButton control. -->
<!--
	如何使用Flex PopUpButton
	MyShareBook.cn 翻译
-->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

	<mx:Script>
		<![CDATA[

			import mx.controls.*;
			import mx.events.*;

			private var myMenu:Menu;

			// Initialize the Menu control, and specify it as the pop up object
			// of the PopUpButton control. 
			private function initMenu():void {
				myMenu = new Menu();
				var dp:Object = [{label: "New Folder"}, {label: "Sent Items"}, {label: "Inbox"}];        
				myMenu.dataProvider = dp;
				myMenu.selectedIndex = 0;       
				myMenu.addEventListener("itemClick", itemClickHandler);
				popB.popUp = myMenu;
				popB.label = "Put in: " + myMenu.dataProvider[myMenu.selectedIndex].label;
			}

			// Define the event listener for the Menu control's itemClick event. 
			private function itemClickHandler(event:MenuEvent):void {
				var label:String = event.item.label;        
				popTypeB.text=String("Moved to " + label);
				popB.label = "Put in: " + label;
				popB.close();
				myMenu.selectedIndex = event.index;
			}

		]]>
	</mx:Script>

    <mx:Panel title="PopUpButton Control Example" height="75%" width="75%" 
        paddingTop="10" paddingBottom="10" paddingRight="10" paddingLeft="10">

        <mx:Label width="100%" color="blue"
            text="Button label contains the name of the last selected menu item." />
        <mx:PopUpButton id="popB" label="Edit" creationComplete="initMenu();" width="135" />
		
        <mx:Spacer height="50" />
        <mx:TextInput id="popTypeB" />
		
    </mx:Panel>		
</mx:Application>