Macromedia flex 2 Manual

Creating Simple MXML Components

The root tag of an MXML component cannot contain an

property. Therefore, if you refer

to the object defined by the root tag in the body of the component, you must use the

this

keyword, as the following example shows:

<?xml version="1.0"?>

<mx:ComboBox xmlns:mx="http://www.adobe.com/2006/mxml"
close="handleCloseEvent(event);">

<mx:Script>
<![CDATA[

import flash.events.Event;

// Define a property to hold the current index.
public var stateIndex:Number;

    private function handleCloseEvent(eventObj:Event):void {
    stateIndex = this.selectedIndex;
    }
  ]]>
</mx:Script>

<mx:dataProvider>
  <mx:String>AK</mx:String>
  <mx:String>AL</mx:String>
</mx:dataProvider>
</mx:ComboBox>

This example defines an event listener for the ComboBox control that updates the

stateIndex

property when the ComboBox control closes.

Applying styles to your custom
component

Along with skins, styles define the look and feel (appearance) of your Flex applications. You
can use styles to change the appearance of a single component, or apply them across all
components.

When working with custom components, you have several options for how you use styles.
You can define your custom components so that they contain no style information at all. That
design allows the application developer who is using your component to apply styles to match
the rest of their application. For example, if you define a custom component to display text,
the application developer can style it to ensure that the font, font size, and font style of your
component match the rest of the application.