flex实现MP3播放功能源码

 
     import flash.media.*;
   import mx.events.SliderEvent ;
   private var _type:int=2;
        private var _sound:Sound;
        private var _channel:SoundChannel;
  private var posNum:Number=0;
        private var _spectrumGraph:BitmapData = new BitmapData(256, 60,
                                             true,
                                             0x000000aa);

//暂停
   private function OnPauseClick():void{
    posNum=_channel.position;
     _channel.stop();
   }

 //停止

   private function OnStopClick():void{
    posNum=0;
     _channel.stop();
   }

   private function OnClick():void{
    hsldLeft.value=1;
   //var  spe:Spectrum=new Spectrum();
            // Create bitmap for spectrum display
   
              // pnlFrame.addEventListener(Event.ENTER_FRAME, onEnterFrame);
            _sound = new Sound(new URLRequest("assets/song.mp3"));
            _channel = _sound.play( posNum );

}

 //输出图形
         public function onEnterFrame():void
        {
         

           // Create the byte array and fill it with data
            var spectrum:ByteArray = new ByteArray(  );
            SoundMixer.computeSpectrum(spectrum);
           
            // Clear the bitmap
            _spectrumGraph.fillRect(_spectrumGraph.rect,
                                     0x00000000);

      
            // Create the left channel visualization
            var i:int;
                               
            if(2==_type){
           for(i=0;i<256;i++) {
                 _spectrumGraph.setPixel32(i,
                               35 + spectrum.readFloat(  ) * 20,
                               0xffffffff);
             }
            }

            if(1==_type){
   
             for(i=0;i<64;i++) {
              _spectrumGraph.fillRect(new Rectangle(4*i,50-spectrum.readFloat(  ) * 50 ,4,spectrum.readFloat(  ) * 50 ),0xffffffff);
             }
            }
   cns.graphics.beginBitmapFill(_spectrumGraph);
   cns.graphics.drawRect(0,0,256,60);
   cns.graphics.endFill();   
    
   var curPos:Number=_channel.position;
   var curLen:Number=_sound.length;
   
   cns.graphics.beginFill(0x0);
   cns.graphics.drawRect(0,80,256,10);
   cns.graphics.endFill();

   cns.graphics.beginFill(0xa0);
   cns.graphics.drawRect(0,80,256*curPos/curLen,10);
   cns.graphics.endFill(); 
        }

//改变输出图形的

  private function OnCnsClick():void{
   _type--;
   if (0>=_type){
    _type=2;
   }
  }

 //改变声音大小
  private function OnChangeVolumn( ):void{
       var transform:SoundTransform = _channel.soundTransform ;
   transform.volume =hsldLeft.value;
   _channel.soundTransform = transform;  
   
   trace("_channel.leftPeak="+_channel.leftPeak*100 +"   "+ "_channel.rightPeak="+_channel.rightPeak*100
    +"_channel.soundTransform.volume"+_channel.soundTransform.volume*100);   
  }
  
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