意思就是：用Flash CS创建一个flash，将需要的fl组件拖进舞台，然后导出swc文件

在FlashBuilder中引入该swc，这时就能在代码中直接new这个fl组件了

How to Use Flash CS’s Components in Flex Builder

To generate the .swc file in Flash CS3, we follow these steps:

1) Make a new Flash CS3 ActionScript 3.0 .fla file.
2) Drag the desired component(s) to the Library. In this example, we’ll drag the TextArea component to the Library.
3) Choose File > Export > Export Movie.
4) For File name, enter v3components.swf. (We don’t even want the generated .swf, but there’s no other way to get the .swc to compile.)
5) Select a folder in which to save the .swf file.
6) Click Save.
7) In the Export Flash Player dialog, check Export SWC.
Click OK.

The preceding steps generate two files, cs3 components.swf and v3components.swc, both of which are placed in the folder selected in Step 5.

Now let’s use cs3 components.swc in a Flex Builder project. Follow these steps:

1) In Flex Builder, select File > New > ActionScript Project.
2) For Project name, enter “V3Test.as”.
3) Click Next.
4) For Main source folder, enter “src”.
5) For Main application file, enter “V3Test.as”.
6) On the Library path tab, click Add SWC.
7) Browse to the v3components.swc file from the preceding procedure.
Click Finish.
9) Update the code in cs Test.as so it looks like this:

package {
  import flash.display.Sprite;
  import fl.controls.TextArea;
  public class V3Test extends Sprite {
    public function V3Test() {
      var t:TextArea = new TextArea();
      t.text = "You're not cookin'";
      addChild(t);
    }
  }

}
10) Run the project.

Flex sdk3就内置了Base64的加/解密工具类
分别是
mx.utils.Base64Encoder
mx.utils.Base64Decoder

Base64Encoder用法如下：

var $orgin:String = this.textOrigi.text;//获取原始字符串
var $base64:Base64Encoder = new Base64Encoder();
$base64.insertNewLines = false;//该值等于true时，输出的结果会自动换行，默认为true，
$base64.encodeUTFBytes($orgin);//这里注意，如果想加密中文就不要使用$base64.encode();
var $result:String = $base64.toString();//输出结果

Base64Decoder用法如下：

				var $origi:String = this.textEncodeResult.text;//获取原始字符串
				var $base64:Base64Decoder = new Base64Decoder();
				$base64.decode($origi);
				var $result:String = $base64.toByteArray().toString();//输出结果，decode类只能输出ByteArray类型的数据，因此要转换成string

完成代码：

<?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">

	<fx:Script>
		<![CDATA[
			import mx.utils.Base64Decoder;
			import mx.utils.Base64Encoder;
			protected function btnEncode_clickHandler(event:MouseEvent):void
			{
				var $orgin:String = this.textOrigi.text;//获取原始字符串
				var $base64:Base64Encoder = new Base64Encoder();
				$base64.insertNewLines = false;//该值等于true时，输出的结果会自动换行，默认为true，
				$base64.encodeUTFBytes($orgin);//这里注意，如果想加密中文就不要使用$base64.encode();
				var $result:String = $base64.toString();//输出结果
				this.textEncodeResult.text = $result
			}

			protected function btnDecode_clickHandler(event:MouseEvent):void
			{
				var $origi:String = this.textEncodeResult.text;//获取原始字符串
				var $base64:Base64Decoder = new Base64Decoder();
				$base64.decode($origi);
				var $result:String = $base64.toByteArray().toString();//输出结果，decode类只能输出ByteArray类型的数据，因此要转换成string
				this.textDecodeResult.text = $result
			}

		]]>
	</fx:Script>

	<mx:Form width="100%">
		<mx:FormItem label="原始字符串：" width="100%">
			<s:TextArea editable="true" id="textOrigi" width="100%" text="在这里输入原始字符串"/>
		</mx:FormItem>
		<mx:FormItem>
			<s:Button id="btnEncode" label="Encode Base64" enabled="{this.textOrigi.text!=''}" click="btnEncode_clickHandler(event)"/>
		</mx:FormItem>
		<mx:FormItem label="Encode 结果：" width="100%">
			<s:TextArea editable="false" id="textEncodeResult" width="100%"/>
		</mx:FormItem>
		<mx:FormItem>
			<s:Button id="btnDecode" enabled="{this.textEncodeResult.text!=''}" label="Decode Base64" click="btnDecode_clickHandler(event)"/>
		</mx:FormItem>
		<mx:FormItem label="Decode 结果：" width="100%">
			<s:TextArea editable="false" id="textDecodeResult" width="100%" text="点击Decode Base64按钮后，这里的结果应该和原始字符串相同"/>
		</mx:FormItem>
	</mx:Form>
</s:Application>