Actionscript 3 ActionScript 3 Flash CS6-淡出音频

我有菜单上播放的背景音乐。我想让它在玩家选择开始按钮startBtn时平滑淡出。你是怎么做到的？ 这是我的密码：

import flash.events.Event;
import flash.events.MouseEvent;
import flash.system.fscommand;
import flash.media.Sound;
import flash.media.SoundChannel;
import flash.net.URLRequest;
import flash.events.Event;
import flash.media.SoundTransform;
import flash.events.MouseEvent;

//Declare MUSIC Variables
var musicSelection:Sound;
var musicChannel:SoundChannel;
var musicTrack:String = "music/dearly_beloved.mp3";
var musicVolume:Number=0.2;
/*var isMuted = false;*/

loadMusic();
function loadMusic():void 
{
    //first stop old sound playing
    SoundMixer.stopAll();
    musicSelection = new Sound();
    musicChannel = new SoundChannel();
    //create and load the required soun
    musicSelection.load(new URLRequest(musicTrack));
    //when loaded - play it
    musicSelection.addEventListener(Event.COMPLETE, musicLoaded);
}

function musicLoaded(evt:Event):void
{
    //finished with this listener
    musicSelection.removeEventListener(Event.COMPLETE, musicLoaded);
    //play music
    playMusic();
}

function playMusic():void
{
    //play the random or selected music
    musicChannel = musicSelection.play();
    //setting the volume control property to the music channel
    musicChannel.soundTransform = new SoundTransform(musicVolume, 0);
    //but add this one to make repeats
    musicChannel.addEventListener(Event.SOUND_COMPLETE, playAgain);
}

function playAgain(evt:Event):void
{
    // remove this listener and repeat
    musicChannel.removeEventListener(Event.SOUND_COMPLETE, playAgain);
    playMusic();
}

这是第二帧的代码：

import flash.events.Event;
import flash.media.SoundTransform;

stop();

optionBtn.addEventListener(MouseEvent.CLICK, goToOption)
function goToOption(event:MouseEvent):void
{
    nextFrame();
}

startBtn.addEventListener(MouseEvent.MOUSE_DOWN, stopMusic);
function stopMusic(event:MouseEvent):void
{
    musicChannel.soundTransform = new SoundTransform(musicVolume, 0);
    while (musicVolume > 0)
    {
        musicVolume--;
    }
}

quitBtn.addEventListener(MouseEvent.MOUSE_DOWN, closeGame);
function closeGame(event:MouseEvent):void 
{
    fscommand("quit");
}

---

使用while。。。只会在一帧内立即减少音乐。您需要做的是添加ENTER_FRAME事件，并在其中减少音乐。大概是这样的：

addEventListener(Event.ENTER_FRAME, onLoop);

var _oldTime:Number = 0;
private function onLoop(e:Event):void
{
   var resultTime:Number = getTimer() - oldTime;
   if(resultTime > 200 )
   {
      musicVolume -= 0.1;
      oldTime += resultTime;
      if(musicVolume <= 0) 
      {
        removeEventListener(Event.ENTER_FRAME,onLoop);
      } 
   }
}

---

根据您想要的速度，尝试不同的值来减小音量，或者何时减小结果时间>200->200ms

您可以使用TweenMax来减小音量：