AVAudioPlayer swift

AVFoundation

initializing

        let file = NSBundle.mainBundle().pathForResource("audio", ofType: "mp3")
        let url = NSURL(fileURLWithPath: file!)

        do{
            self.audioPlayer = try AVAudioPlayer(contentsOfURL: url)
        }catch let error as NSError {
            print(error.description)
        }

other function

– initWithData:error:
– initWithData:fileTypeHint:error:
– initWithContentsOfURL:fileTypeHint:error:

Controlling Function

function play() -> Bool
function pause()
function stop()
function prepareToPlay() -> Bool 

A Boolean value that indicates whether the audio player is playing(YES) or not(NO). (read-only)
var playing: Bool {get} 

var volume:Float  // ranging from 0.0 through 1.0 on a linear scale

setting background play
https://developer.apple.com/library/ios/qa/qa1668/_index.html

往plist文件加个 key="Required background modes" item 0 = "App plays audio or streams audio/video using AirPlay"
code

     let audioSession = AVAudioSession.sharedInstance()
       do {
           try audioSession.setCategory(AVAudioSessionCategoryPlayback)
       }catch let error as NSError {print(error.description)}

引用
(http://coderzhang.xyz/2016/04/02/%E4%BD%BF%E7%94%A8avaudioplayer%E6%92%AD%E6%94%BE%E9%9F%B3%E9%A2%91/)
''prepareToPlay方法会取得需要的音频硬件并预加载到Audio Queue的缓冲区,这样可以降低play方法调用后准备播放产生的延时.prepareToPlay方法如果没有被手动显式调用,那么当调用play方法时会隐式调用.''

volume:播放器的音量独立于系统音量,可以通过对播放器音量的处理实现很多有趣的效果,比如声音的渐隐效果
pan:允许使用立体声播放,范围从-1.0(极左)到1.0(极右),默认为0,居中
rate:iOS 5以后允许用户在不改变音调的情况下调整播放速率,范围从0.5(半速)到2.0(2倍速)
numberOfLoops:可以设置播放器循环播放次数,设置为-1则表示无限循环