Problem in drawing line in script tag of mxml file

Question

hai i am new in flex .i was trying to draw line in mxml(using mxml ) and did it.
then i try this in actionscript by making as file and shape class object again did it
but
when i put that specific function in <fx:script> tag of mxml file and call it by mouseover method it is not drawing a line.i am sure that on mouse over function was called .but dont know why line is nort draw here.
Here is my code:
<?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">
    <fx:Script>
        <![CDATA[
        import flash.display.Shape;
        var s:Shape = new Shape();
        public function myMain():void
            // Launch your application by right clicking within this class and select: Deubg As > FDT SWF Application
        so.text="button is cliked";
        s.graphics.lineStyle(3, 0x00FF00,.5);       
        s.graphics.lineTo(200, 200);
        this.addChild(s);
        so.text="button is cliked";
        ]]>
    </fx:Script>
    <mx:Label alpha=".3" id="so" mouseOver="myMain()" text="Button"/>
</s:Application>
Can anyone tell me where i am going wrong.

Answer 1

It's a good idea to run you code in the debugger because you will be notified of runtime exceptions that the release version of the Flash Player will not show you. Here's the runtime error I got when running your example:
Error: addChild() is not available in this class. Instead, use addElement() or modify the skin, if you have one.
     atspark.components.supportClasses::SkinnableComponent/addChild()[frameworks\projects\ spark\src\spark\components\supportClasses\SkinnableComponent.as:1118]
     at myMain()[b.mxml:19]
     at __so_mouseOver()[b.mxml:27]
The problem with your app is it is calling addChild(), which is not supported on s:Application. You need to call addElement() instead. addElement() only takes an object of type IVisualElement so you need to make your shape a UIComponent.  Try this:
            import mx.core.UIComponent;
            private var s:UIComponent = new UIComponent();
            public function myMain():void
                // Launch your application by right clicking within this class and select: Deubg As > FDT SWF Application
                so.text="button is cliked";
                s.graphics.lineStyle(3, 0x00FF00,.5);
                s.graphics.lineTo(200, 200);
                this.addElement(s);
                so.text="button is cliked";
-Darrell