Setting the border alpha on a Spark DropDownList control in Flex 4

The following example shows how you can set the border alpha on a Spark DropDownList control’s popup menu in Flex 4 by setting the borderAlpha style.

The following example(s) require Flash Player 10 and the Adobe Flex 4 SDK. To download the Adobe Flash Builder 4 trial, see To download the latest nightly build of the Flex 4 SDK, see

For more information on getting started with Flex 4 and Flash Builder 4, see the official Adobe Flex Team blog.

<?xml version="1.0" encoding="utf-8"?>
<!-- -->
<s:Application name="Spark_DropDownList_borderAlpha_test"
        <s:Label text="borderAlpha:" />
        <s:HSlider id="sl"
                minimum="0.0" maximum="1.0"
                snapInterval="0.1" stepSize="0.1"
                change="ddl.openDropDown();" />
    <s:DropDownList id="ddl"
            horizontalCenter="0" top="20">
            <s:ArrayList source="[One,Two,Three,Four,Five,Six,Seven]" />

This entry is based on a beta version of the Flex 4 SDK and therefore is very likely to change as development of the Flex SDK continues. The API can (and will) change causing examples to possibly not compile in newer versions of the Flex 4 SDK.