package {
    //导入类
    //Sprite是一个只有一帧的MovieClip,相对于MovieClip少了帧和场景...
    import flash.display.Sprite;
    //事件类
    import flash.events.*;
    //声音类
    import flash.media.Sound;
	//混音器类
	import flash.media.SoundMixer;
	//声音通道类(暂时这么翻吧)
	import flash.media.SoundChannel;
    //URLRequest类
    import flash.net.URLRequest;
	//二进制数组类
	import flash.utils.ByteArray;
    //定义类
    public class SwfdongSound extends Sprite {
        //声明MP3路径
        private var url:String = "MySound.mp3";
        //声明一个Sound对象
        private var DongSound:Sound = new Sound();
		//声明一个SoundChannel对象
        private var sChannel:SoundChannel;
		//声明一个ByteArray对象
        private var bArray:ByteArray = new ByteArray();
		//声明一个数组对象
        private var Ary:Array;
		//声明一个数字对象
		private var n:Number = 0;
        //初始化函数
        public function SwfdongSound() {
			var req:URLRequest = new URLRequest(url);
			DongSound.load(req);
            //播放
            DongSound.play();
			//添加一个EnterFrame的侦听器,同以前的this.onEnterFrame=showBar();
			this.addEventListener(Event.ENTER_FRAME,showBar);
    }
private function showBar(event:Event){
        n = 0;
		//清除绘图
        this.graphics.clear();
		//将当前声音输出为ByteArray
        SoundMixer.computeSpectrum(bArray,true,0);
        for(var i=0; i < 256; i=i+16){
			    //在ByteArray中读取一个32位的单精度浮点数(这个是livedoc上写的,实际就是把数据流读取成浮点数)
                n = bArray.readFloat();
				//这个实际作用是把n扩大一下
                var num:Number = n*360;
				//设置线条样式,颜色绿色,宽度10,透明度100
                this.graphics.lineStyle(10,0x99FF00,100,false,"noSacle","none");
				//移动到x坐标50+i,y坐标200的位置
				this.graphics.moveTo(50+i,200);
				//向上画图
                this.graphics.lineTo(50+i,200-num/5);
        }
   
      }  
    }
}