Setting the background color and background alpha on a Flex PopUpButton control’s pop up menu

The following example shows how you can change the background color and alpha of a PopUpButton control’s pop up menu in Flex by setting the popUpStyleName, backgroundAlpha, and backgroundColor styles.

<? xml version="1.0" ?>
<!--  http://blog.flexexamples.com/2008/01/17/setting-the-background-color-and-background-alpha-on-a-flex-popupbutton-controls-pop-up-menu/  -->
< mx:Application  xmlns:mx ="http://www.adobe.com/2006/mxml"
        layout ="vertical"
        verticalAlign ="top"
        backgroundColor ="white" >

     < mx:Script >
         <![CDATA[
            import mx.controls.Menu;
            import mx.events.MenuEvent;

            [Bindable]
            private var menu:Menu;

            private function initMenu():void {
                menu = new Menu();
                menu.dataProvider = arr;
                menu.setStyle("themeColor", "black");
            }
         ]]>
     </ mx:Script >

     < mx:Array  id ="arr" >
         < mx:Object  label ="Button"   />
         < mx:Object  label ="ButtonBar"   />
         < mx:Object  label ="ColorPicker"   />
         < mx:Object  label ="ComboBox"   />
     </ mx:Array >

     < mx:Style >
        .myPop {
            backgroundAlpha: 0.7;
            backgroundColor: black;
            borderStyle: none;
            color: white;
        }
     </ mx:Style >

     < mx:ApplicationControlBar  dock ="true" >
         < mx:PopUpButton  id ="popUpButton"
                label ="Select a control"
                popUp ="{menu}"
                popUpStyleName ="myPop"
                preinitialize ="initMenu();"   />
     </ mx:ApplicationControlBar >

     < mx:VBox  backgroundColor ="haloSilver"
            width ="100%"
            height ="100%"   />

</ mx:Application >