Flex动态设置Button中的icon指向外网图片源

IconUtility.as

   
     

    
      
    
      package
    
      
{
 
    
      import
    
       flash.display.BitmapData;
 
    
      import
    
       flash.display.Loader;
 
    
      import
    
       flash.display.LoaderInfo;
 
    
      import
    
       flash.events.Event;
 
    
      import
    
       flash.geom.Matrix;
 
    
      import
    
       flash.net.URLRequest;
 
    
      import
    
       flash.system.LoaderContext;
 
    
      import
    
       flash.utils.Dictionary; 
 
    
      import
    
       mx.containers.accordionClasses.AccordionHeader;
 
    
      import
    
       mx.controls.tabBarClasses.Tab;
 
    
      import
    
       mx.core.BitmapAsset;
 
    
      import
    
       mx.core.UIComponent;

 
    
      public
    
       
    
      class
    
       IconUtility 
    
      extends
    
       BitmapAsset
 {
 
    
      private
    
       
    
      static
    
       var dictionary:Dictionary; 
 
    
      public
    
       
    
      static
    
       function getClass( target:UIComponent, source:String, width:Number 
    
      =
    
       NaN, height:Number 
    
      =
    
       NaN ):Class 
 {
 
    
      if
    
      (
    
      !
    
      dictionary) 
 {
 dictionary 
    
      =
    
       
    
      new
    
       Dictionary(
    
      false
    
      );
 }
 
    
      //
    
      if(source is String) 
 
    
      //
    
      {
    
      

    
       var loader:Loader 
    
      =
    
       
    
      new
    
       Loader();
 loader.load(
    
      new
    
       URLRequest(source as String), 
    
      new
    
       LoaderContext(
    
      true
    
      ));
 
    
      //
    
      source = loader;
 
    
      //
    
      }
    
      

    
       dictionary[target] 
    
      =
    
       { source:loader, width:width, height:height };
 
    
      return
    
       IconUtility;
 }

 
    
      public
    
       function IconUtility():
    
      void
    
       
 {
 addEventListener(Event.ADDED, addedHandler, 
    
      false
    
      , 
    
      0
    
      , 
    
      true
    
      )
 }

 
    
      private
    
       function addedHandler(event:Event):
    
      void
    
       
 {
 
    
      if
    
      (parent) 
 {
 
    
      if
    
      (parent is AccordionHeader) 
 {
 var header:AccordionHeader 
    
      =
    
       parent as AccordionHeader;
 getData(header.data);
 } 
 
    
      else
    
       
    
      if
    
      (parent is Tab) 
 {
 var tab:Tab 
    
      =
    
       parent as Tab;
 getData(tab.data);
 } 
 
    
      else
    
       
 {
 getData(parent);
 }
 }
 }

 
    
      private
    
       function getData(object:Object):
    
      void
    
       
 {
 var data:Object 
    
      =
    
       dictionary[object];
 
    
      if
    
      (data) 
 {
 var source:Object 
    
      =
    
       data.source;
 
    
      if
    
      (data.width 
    
      >
    
       
    
      0
    
       
    
      &&
    
       data.height 
    
      >
    
       
    
      0
    
      ) 
 {
 bitmapData 
    
      =
    
       
    
      new
    
       BitmapData(data.width, data.height, 
    
      true
    
      , 
    
      0x00FFFFFF
    
      );
 }
 
    
      if
    
      (source is Loader) 
 {
 var loader:Loader 
    
      =
    
       source as Loader;
 
    
      if
    
      (
    
      !
    
      loader.content) 
 {
 loader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler, 
    
      false
    
      , 
    
      0
    
      , 
    
      true
    
      );
 } 
 
    
      else
    
       
 {
 displayLoader(loader);
 }
 }
 }
 }

 
    
      private
    
       function displayLoader( loader:Loader ):
    
      void
    
       
 {
 
    
      if
    
      (
    
      !
    
      bitmapData) 
 {
 bitmapData 
    
      =
    
       
    
      new
    
       BitmapData(loader.content.width, loader.content.height, 
    
      true
    
      , 
    
      0x00FFFFFF
    
      );
 }

 bitmapData.draw(loader, 
    
      new
    
       Matrix(bitmapData.width
    
      /
    
      loader.width, 
    
      0
    
      , 
    
      0
    
      , bitmapData.height
    
      /
    
      loader.height, 
    
      0
    
      , 
    
      0
    
      ));

 
    
      if
    
      (parent is UIComponent) 
 {
 var component:UIComponent 
    
      =
    
       parent as UIComponent;
 component.invalidateSize();
 }
 }

 
    
      private
    
       function completeHandler(event:Event):
    
      void
    
       
 {
 
    
      if
    
      (event 
    
      &&
    
       event.target 
    
      &&
    
       event.target is LoaderInfo) 
 {
 displayLoader(event.target.loader as Loader);
 }
 }
 }
}
   
     

 

main.mxml

   
     

    
      
    
      <?
    
      xml version="1.0" encoding="utf-8"
    
      ?>
    
      

    
      <
    
      mx:Application 
    
      xmlns:mx
    
      ="http://www.adobe.com/2006/mxml"
    
       layout
    
      ="absolute"
    
      >
    
      
 
    
      <
    
      mx:Script
    
      >
    
      
 
    
      <![CDATA[
    
      
 import com.IconUtility;
 public function open():void
 { 
 navigateToURL(new URLRequest("http://hi.baidu.com/woaidelphi/"), "_blank"); 
 } 
 
    
      ]]>
    
      
 
    
      </
    
      mx:Script
    
      >
    
      
 
    
      <
    
      mx:Button 
    
      id
    
      ="button"
    
       label
    
      ="Button"
    
       
 icon
    
      ="
    
      {IconUtility.getClass(button, 'http://hiphotos.baidu.com/woaidelphi/abpic/item/ace9cd3836b88206b9998fe9.jpg')}
    
      "
    
       x
    
      ="488"
    
       y
    
      ="233"
    
       width
    
      ="278"
    
       height
    
      ="107"
    
      
 click
    
      ="open()"
    
      />
    
      

    
      </
    
      mx:Application
    
      >