How can I change Label's text using ActionScript?

Question

Hi~ everyone~
I want change Label's text using ActionScript.
Test.mxml
<?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" minWidth="955" minHeight="600" initialize="init()">
<fx:Script>
  <![CDATA[
   private function init():void{
    var btn:BtnScript = new BtnScript();
    this.addElement(btn);
  ]]>
</fx:Script>
<fx:Declarations>
  <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<s:Label x="182" y="149" text="Label" id="lbl"/>
</s:Application>
BtnScript.as
package
import flash.events.MouseEvent;
import mx.controls.Alert;
import spark.components.Button;
public class BtnScript extends Button
  public function BtnScript()
   super();
   this.addEventListener(MouseEvent.CLICK, eventHandler);
  private function eventHandler(event:MouseEvent):void{
          // lbl.text = "changed text";
       // HOW CAN I ACCESS LABEL IN MXML FILE?
I'm about to learn flex. Please help me.
Thanks in advanced.

Answer 1

You could achive this very easily(but this shouldn't be used in production code as it'll be difficult to manage as the project grows) by defining a static data member varibale of DataType Label something like below, (modified/added code in BOLD)
Test.mxml
<?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" minWidth="955" minHeight="600" initialize="init()"
      creationComplete="creationCompleteHandler(event)">
<fx:Script>
  <![CDATA[
   private function init():void{
     var btn:BtnScript = new BtnScript();
     this.addElement(btn);
   private function creationCompleteHandler(event:FlexEvent):void{
     Model.someLabel = lbl;
  ]]>
</fx:Script>
<fx:Declarations>
  <!-- Place non-visual elements (e.g., services, value objects) here -->
</fx:Declarations>
<s:Label x="182" y="149" text="Label" id="lbl"/>
</s:Application>
BtnScript.as
package
  import flash.events.MouseEvent;
  import mx.controls.Alert;
  import spark.components.Button;
  public class BtnScript extends Button
    public function BtnScript()
      super();
      this.addEventListener(MouseEvent.CLICK, eventHandler);
    private function eventHandler(event:MouseEvent):void{
          // lbl.text = "changed text";
      // Now use Model.someLabel which is basically 'lbl'.
      Model.someLabel.text = "changed text";  //Mission Accomplished....
Model.as
package
  public class Model
    public static someLabel:Label;
Note: This approach is just to give you an idea but instead should use the MVC pattern.