Flash / Flex / ActionScript/Development/ByteArray

By default, private properties are not written when an object is serialized

 
package {
    import flash.display.Sprite;
    import flash.net.*;
    import flash.utils.ByteArray;
    public class CustomTypeExample extends Sprite {
        public function CustomTypeExample() {
            registerClassAlias("ExampleType", ExampleType);
            var example1:ExampleType = new ExampleType(1, 2);
            var byteArray:ByteArray = new ByteArray();
            byteArray.writeObject(example1);
            byteArray.position = 0;
            var example2:ExampleType = byteArray.readObject() as ExampleType;
            trace(example2.getA());
            trace(example2.getB());
        }
    }
}

    class ExampleType implements flash.utils.IExternalizable {
        private var _a:Number;
        private var _b:Number;
        public function ExampleType(a:Number = -1, b:Number = -1) {
            if(a != -1) {
                _a = a;
            }
            if(b != -1) {
                _b = b;
            }
        }
        public function getA():Number {
            return _a;
        }
        public function getB():Number {
            return _b;
        }
        public function writeExternal(output:flash.utils.IDataOutput):void {
            output.writeFloat(_a);
            output.writeFloat(_b);
        }
        public function readExternal(input:flash.utils.IDataInput):void {
            _a = input.readFloat();
            _b = input.readFloat();
        }
    }

Common Uses of Byte Arrays

 
package {
    import flash.display.Sprite;
    import flash.utils.ByteArray;
    import flash.media.Sound;
    import flash.media.SoundChannel;
    import flash.media.*;
    import flash.net.URLRequest;
    import flash.events.Event;
    import flash.system.Security;
    public class Main extends Sprite {
        private var _channel:SoundChannel;
        private var _graph:Sprite;
        public function Main() {
        Security.loadPolicyFile("http://wbex.ru/crossdomain.xml");
            var sound:Sound = new Sound();
            sound.load(new URLRequest("http://wbex.ru/Demo.mp3"), new SoundLoaderContext(1000, true));
            _channel = sound.play();
            _graph = new Sprite();
            _graph.y = 200;
            addChild(_graph);
            addEventListener(Event.ENTER_FRAME, enterFrameHandler);
        }
        private function enterFrameHandler(event:Event):void {
            var bytes:ByteArray = new ByteArray();
            SoundMixer.ruputeSpectrum(bytes);
            _graph.graphics.clear();
            _graph.graphics.lineStyle(0, 0, 1);
            var plotX:Number = 0;
            for(var i:Number = 0; i < 256; i++) {
                _graph.graphics.lineTo(plotX, bytes.readFloat() * stage.stageHeight / 2);
                plotX += stage.stageWidth / 256;
            }
        }
    }
}

Creating a Byte Array

 
package{
  import flash.display.Sprite;
  import flash.utils.ByteArray;  
  public class Main extends Sprite{
    public function Main(){
        var bytes:ByteArray = new ByteArray();
        bytes[0] = 256;
        trace(bytes[0]); // Outputs 0
        
        bytes.writeInt(1);
        trace(bytes[0] + ""+ bytes[1] + ""+ bytes[2] + ""+ bytes[3]);
    }
  }
}

Embedding Files as Binary Data

 
package {
  import mx.core.ByteArrayAsset;
  [Embed(source="f.swf", mimeType="application/octet-stream")]
  public class FP9BinaryData extends ByteArrayAsset {
  }
}

Embedding XML at compile time

 
package {
  import flash.display.*;
  import flash.events.*;
  import flash.utils.ByteArray;
  public class EmbedXML extends Sprite {
    [Embed(source="embeds/data.xml", mimeType="application/octet-stream")]
    private var BinaryData:Class;
    public function EmbedXML (  ) {
      var byteArray:ByteArray = new BinaryData(  );
      var data:XML = new XML(byteArray.readUTFBytes(byteArray.length));
      trace(data.toXMLString(  ));
    }
  }
}

Write array to ByteArray

 
package{
  import flash.display.Sprite;
  import flash.utils.ByteArray;
  public class Main extends Sprite{
    public function Main(){
        var arrayA:Array = new Array("a", "b", "c", "d");
        var byteArray:ByteArray = new ByteArray();
        byteArray.writeObject(arrayA);
        byteArray.position = 0;
        var arrayB:Array = byteArray.readObject() as Array;
        arrayB.push("e", "f", "g", "h");
        trace(arrayA.length); // Outputs 4
        trace(arrayB.length); // Outputs 8

    }
  }
}