Flash CS4如何控制动画声音的停止和播放

/*
As3Sound.as
*/
package {
import flash.display.Sprite;
import flash.events.*;
import flash.media.Sound;
import flash.media.SoundChannel;
import .URLRequest;
import flash.utils.Timer;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
import flash.filters.DropShadowFilter;
public class As3Sound extends Sprite {
private var url:String = "/music/lib/myRussia.mp3";
private var soundFactory:Sound;
private var channel:SoundChannel;
private var positionTimer:Timer;
private var play_btn:Sprite;
private var stop_btn:Sprite;
private var d_filtersropShadowFilter=new DropShadowFilter(5,45,0x000000,80,8,8);
//用于记录音乐现在是否为暂停状态
private var bSoundStop:Boolean = false;
public function As3Sound() {
var sxl_txt:TextField = new TextField();
sxl_txt.text="CS4中如何控制声音的播放或停止的";
sxl_txt.autoSize=TextFieldAutoSize.LEFT;
sxl_txt.x=stage.stageWidth/2-sxl_txt.width/2;
sxl_txt.y=20;
addChild(sxl_txt);
var mp3_request:URLRequest = new URLRequest(url);
soundFactory = new Sound();
//成功加载数据后
soundFactory.addEventListener(PLETE, completeHandler);
//在存在可用于 MP3 声音的 ID3 数据时
soundFactory.addEventListener(Event.ID3, id3Handler);
//加载音乐错误时
soundFactory.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
//音乐加载中...
soundFactory.addEventListener(ProgressEvent.PROGRESS, progressHandler);
soundFactory.load(mp3_request);
channel = soundFactory.play();
//音乐播放完成
channel.addEventListener(Event.SOUND_COMPLETE, soundCompleteHandler);
//用Timer监听音乐的播放进度
positionTimer = new Timer(1000);
positionTimer.addEventListener(TimerEvent.TIMER, positionTimerHandler);
positionTimer.start();
//创建一个按钮，用于播放音乐
play_btn = new Sprite();
play_btn.graphics.beginFill(0xFFCC32);
play_btn.graphics.drawRoundRect(0, 0, 70, 18, 10, 10);
play_btn.graphics.endFill();
var play_txt:TextField = new TextField();
play_txt.text = "播放";
play_txt.x=18;
play_btn.x=50;
play_btn.y=100;
play_txt.selectable = false;
play_btn.addChild(play_txt);
play_btn.filters=[d_filters];
play_btn.addEventListener(MouseEvent.CLICK, soundPlay);
addChild(play_btn);
//创建一个按钮，用于停止音乐
stop_btn = new Sprite();
stop_btn.graphics.beginFill(0xFFCC32);
stop_btn.graphics.drawRoundRect(0, 0, 70, 18, 10, 10);
stop_btn.graphics.endFill();
stop_btn.x=130;
stop_btn.y=100;
var stop_txt:TextField = new TextField();
stop_txt.x=18;
stop_txt.text = "暂停";
stop_txt.selectable = false;
stop_btn.addChild(stop_txt);
stop_btn.filters=[d_filters];
stop_btn.addEventListener(MouseEvent.CLICK, soundStop);
addChild(stop_btn);

}
//监听音乐的播放进度
private function positionTimerHandler(event:TimerEvent):void {
var ybf:int = channel.position.toFixed(0);
var zcd:int = soundFactory.length;
var bfs:int = Math.floor(ybf/zcd*100);

//trace("音乐总长度："+zcd, "音乐已播放："+ybf, "播放进度为："+bfs+"%");
}
//加载音乐完成时
private function completeHandler(event:Event):void {
//trace("加载音乐完成: " + event);
}
//在存在可用于MP3声音的ID3数据时
private function id3Handler(event:Event):void {
//trace("音乐的ID3信息如下:");
for (var s in soundFactory.id3) {
//trace("t", s, ":", soundFactory.id3[s]);
}
//trace("关于ID3信息介绍，请参见Sound类-->属性-->id3");
}
//加载音乐错误时
private function ioErrorHandler(event:Event):void {
//trace("加载音乐错误，错误信息如下：" + event);
positionTimer.stop();
}
//加载音乐时
private function progressHandler(eventrogressEvent):void {
var yjz:int = event.bytesLoaded;
var zcd:int = event.bytesTotal;
var bfs:int = Math.floor(yjz/zcd*100);
//trace("音乐总长度："+zcd,"已加载: "+yjz, "加载进度为："+bfs+"%");
}
//音乐播放完成
private function soundCompleteHandler(event:Event):void {
//trace("音乐播放完成: " + event);
positionTimer.stop();
}
//点击播放按钮事件
private function soundPlay(event:MouseEvent):void {
if (bSoundStop) {
bSoundStop = false;
channel = soundFactory.play(channel.position.toFixed(0));
}
}
//点击停止按钮事件
private function soundStop(event:MouseEvent):void {
if (!bSoundStop) {
bSoundStop = true;
channel.stop();
}
}
}
}