Question

I have a Flex application in which I draw a rectangle using:

<s:Rect height="20" width="115" top="1" id="myRect">
    <s:stroke>
        <s:SolidColorStroke color="#FF0000" weight="2" alpha="0"/>
    </s:stroke>
</s:Rect>   

I want to set the value of alpha for myRect dynamically. Is it possible to set alpha using Actionscript? If so, how to access the alpha property?

I thought something like this would work, but I’m getting error Access of undefined property SolidColorStroke:

searchRect.stroke.SolidColorStroke.alpha=1;

Answer 1

Give the s:SolidColorStroke an id, as in:

<s:SolidColorStroke id="stroke"

Then you can set alpha such as:

 stroke.alpha = 0.5;

This example updates the alpha based on a slider:

<?xml version="1.0" encoding="utf-8"?>
<s:Application 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:layout>
        <s:VerticalLayout />
    </s:layout>

    <s:Rect height="20"
            width="115"
            top="1"
            id="myRect">
        <s:stroke>
            <s:SolidColorStroke id="stroke"
                                color="#FF0000"
                                weight="2"
                                alpha="0" />
        </s:stroke>
    </s:Rect>

    <s:HSlider id="slider"
               valueCommit="{stroke.alpha = slider.value}"
               value="0.5"
               minimum="0"
               maximum="1"
               stepSize="0.1"
               snapInterval="0.1" />

</s:Application>