Full code after the jump.

To use the following code, you must have Flash Player 10 and [...]]]> The following example shows how you can apply an easing function to a property animation in Flex with the beta Gumbo SDK and Flash Player 10 by setting the easingFunction property on the AnimateProperties object instance.

Full code after the jump.

To use the following code, you must have Flash Player 10 and a Flex Gumbo SDK installed in your Flex Builder 3. For more information on downloading and installing the Gumbo SDK into Flex Builder 3, see “Using the beta Gumbo SDK in Flex Builder 3″.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/08/12/using-an-easing-function-with-the-animateproperties-class-in-flex-and-flash-player-10/ -->
<Application name="AnimateProperties_easingFunction_test"
        xmlns="http://ns.adobe.com/mxml/2009"
        xmlns:mx="library:adobe/flex/halo"
        layout="flex.layout.BasicLayout">

    <Declarations>
        <AnimateProperties id="animateProps"
                easingFunction="Elastic.easeOut"
                duration="4000">
            <propertyValuesList>
                <PropertyValuesHolder property="rotationY"
                        values="[0, 360]" />
            </propertyValuesList>
        </AnimateProperties>
    </Declarations>

    <Script>
        import mx.effects.easing.*;

        private function animateRotationY():void {
            animateProps.stop();
            animateProps.play([img]);
        }
    </Script>

    <Button label="Rotate y-axis"
            top="10"
            left="10"
            click="animateRotationY();" />

    <mx:Image id="img"
            source="@Embed('Fx.png')"
            width="100"
            height="100"
            horizontalCenter="0"
            verticalCenter="0" />

</Application>

View source is enabled in the following example.

You can also set the easingFunction property in ActionScript, as seen in the following example:

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/08/12/using-an-easing-function-with-the-animateproperties-class-in-flex-and-flash-player-10/ -->
<Application name="AnimateProperties_easingFunction_test"
        xmlns="http://ns.adobe.com/mxml/2009"
        xmlns:mx="library:adobe/flex/halo"
        layout="flex.layout.BasicLayout"
        initialize="init();">

    <Script>
        import flex.effects.AnimateProperties;
        import flex.effects.PropertyValuesHolder;
        import mx.effects.easing.*;

        private var animateProps:AnimateProperties;

        private function init():void {
            var rotYProp:PropertyValuesHolder;
            rotYProp = new PropertyValuesHolder("rotationY", [0, 360]);
            animateProps = new AnimateProperties();
            animateProps.easingFunction = Elastic.easeOut;
            animateProps.duration = 4000; // ms
            animateProps.propertyValuesList = [rotYProp];
        }

        private function animateRotationY():void {
            animateProps.stop();
            animateProps.play([img]);
        }
    </Script>

    <Button label="Rotate y-axis"
            top="10"
            left="10"
            click="animateRotationY();" />

    <mx:Image id="img"
            source="@Embed('Fx.png')"
            width="100"
            height="100"
            horizontalCenter="0"
            verticalCenter="0" />

</Application>