Toggling the drop shadow on the Spark DropDownList control in Flex 4

The following example shows how you can toggle the drop shadow on the Spark DropDownList control in Flex 4 by setting the Boolean dropShadowVisible style.

The following example(s) require Flash Player 10 and the Adobe Flex 4 SDK. To download the Adobe Flash Builder 4 trial, see www.adobe.com/products/flex/. To download the latest nightly build of the Flex 4 SDK, see opensource.adobe.com/wiki/display/flexsdk/Download+Flex+4.

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"?>
<!-- http://blog.flexexamples.com/2010/06/21/toggling-the-drop-shadow-on-the-spark-dropdownlist-control-in-flex-4/ -->
<s:Application name="Spark_DropDownList_dropShadowVisible_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:controlBarContent>
        <s:CheckBox id="cb"
                label="dropShadowVisible"
                selected="true"
                change="cb_changeHandler(event);" />
    </s:controlBarContent>
 
    <fx:Script>
        <![CDATA[
            protected function cb_changeHandler(evt:Event):void {
                ddl.openDropDown();
            }
        ]]>
    </fx:Script>
 
    <s:DropDownList id="ddl"
            requireSelection="true"
            dropShadowVisible="{cb.selected}"
            horizontalCenter="0" top="20">
        <s:dataProvider>
            <s:ArrayList source="[One,Two,Three,Four,Five,Six,Seven,Eight,Nine,Ten]" />
        </s:dataProvider>
    </s:DropDownList>
 
</s:Application>

View source is enabled in the following example.

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You can also set the dropShadowVisible style in an external .CSS file or >Style> block, as seen in the following example:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2010/06/21/toggling-the-drop-shadow-on-the-spark-dropdownlist-control-in-flex-4/ -->
<s:Application name="Spark_DropDownList_dropShadowVisible_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
 
    <fx:Style>
        @namespace s "library://ns.adobe.com/flex/spark";
 
        s|DropDownList {
            dropShadowVisible: false;
        }
    </fx:Style>
 
    <s:DropDownList id="ddl"
            requireSelection="true"
            horizontalCenter="0" top="20">
        <s:dataProvider>
            <s:ArrayList source="[One,Two,Three,Four,Five,Six,Seven,Eight,Nine,Ten]" />
        </s:dataProvider>
    </s:DropDownList>
 
</s:Application>

Or you can set the dropShadowVisible style using ActionScript, as seen in the following example:

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2010/06/21/toggling-the-drop-shadow-on-the-spark-dropdownlist-control-in-flex-4/ -->
<s:Application name="Spark_DropDownList_dropShadowVisible_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/mx">
    <s:controlBarContent>
        <s:CheckBox id="cb"
                label="dropShadowVisible"
                selected="true"
                change="cb_changeHandler(event);" />
    </s:controlBarContent>
 
    <fx:Script>
        <![CDATA[
            protected function cb_changeHandler(evt:Event):void {
                ddl.setStyle("dropShadowVisible", cb.selected);
                ddl.openDropDown();
            }
        ]]>
    </fx:Script>
 
    <s:DropDownList id="ddl"
            requireSelection="true"
            horizontalCenter="0" top="20">
        <s:dataProvider>
            <s:ArrayList source="[One,Two,Three,Four,Five,Six,Seven,Eight,Nine,Ten]" />
        </s:dataProvider>
    </s:DropDownList>
 
</s:Application>

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.