Flash如何控制动画或声音的停止与播放

今天有闪友问到如何控制AS3中的声音问题，用下面的小实例说明：

/*

As3Sound.as

*/

package {

import flash.display.Sprite;

import flash.events.*;

import flash.media.Sound;

import flash.media.SoundChannel;

import flash.net.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 = "http://XXX.com/music/XXX.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(Event.COMPLETE, 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();

}

}

}

}