将业务和功能分开

功能就是功能，业务就是业务，不能将两者揉在一起，这样可以提高d代码复用率，

举例：

//  AudioPlayer.swift//  DropProjectsGame////  Created by lin kang on 17/1/29.//  Copyright © 2017年 lin kang. All rights reserved.//import UIKitimport AVFoundationenum GameAudioType{    case backround_one,    backround_two,    backround_three,    backround_four,    collison,    fallingon,    gameOver,    gameWin        func getStateMusicName() -> String! {        switch self {        case .backround_one:            return "backGroundMusic_1.mp3";        case .backround_two:            return "backGroundMusic_2.mp3"        case .backround_three:            return "backGroundMusic_3.mp3"        case .backround_four:            return "backGroundMusic_4.mp3"        case .collison:            return "collision.wav"        case .fallingon:            return "fallingOn.mp3"        case .gameOver:            return "gameOver.wav"        case .gameWin:            return "gameWin.wav"        }    }}class AudioPlayer: NSObject,AVAudioPlayerDelegate {    private var audioBackGourndMusicPlayer:AVAudioPlayer!    private var audioInstantMusicPlayer:AVAudioPlayer!    public var  instantMusicRrepeateTime:Int = 0;        func playSoundWithSoundType(soundType:GameAudioType )  {        let soundName = soundType.getStateMusicName()        let path = Bundle.main.path(forResource: soundName, ofType: nil)        let url = URL(fileURLWithPath: path!)                do {            if soundType  == .backround_one ||                soundType == .backround_two ||                soundType == .backround_three ||                soundType == .backround_four{                let sound = try AVAudioPlayer(contentsOf: url)                sound.delegate = self;                if audioBackGourndMusicPlayer != nil{                    audioBackGourndMusicPlayer.stop();                    audioBackGourndMusicPlayer = nil;                }               audioBackGourndMusicPlayer = sound               audioBackGourndMusicPlayer.play()            }else{                if audioInstantMusicPlayer == nil{                    let sound = try AVAudioPlayer(contentsOf: url)                    sound.delegate = self;                    audioInstantMusicPlayer = sound                    audioInstantMusicPlayer.play()                }            }        } catch{            print("\(soundName) 不能播放!")        }    }        func stopSoundWithSoundType(soundType:GameAudioType) {        if soundType  == .backround_one ||            soundType == .backround_two ||            soundType == .backround_three ||            soundType == .backround_four{            if audioBackGourndMusicPlayer != nil{                audioBackGourndMusicPlayer.stop();                audioBackGourndMusicPlayer = nil;            }        }    }        public func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool)    {        if instantMusicRrepeateTime > 0 {            audioInstantMusicPlayer.play()            instantMusicRrepeateTime -= 1;        }else {            audioInstantMusicPlayer = nil;        }                //背景音乐循环播放        if player == audioBackGourndMusicPlayer{            player.play()        }    }        /* if an error occurs while decoding it will be reported to the delegate. */     public func audioPlayerDecodeErrorDidOccur(_ player: AVAudioPlayer, error: Error?)     {}}

这是我之前的代码，将音乐类型和播放音乐的功能混合在了一起，类型是属于业务的，比如像是collison,fallingon,等，一旦类型变了，那么我的这个接口也就没办法用了。

于是，我单独写了一个和类型无关的音乐播放类，返回AVAudioCustomPlayer的uuid, 继承AVAudioPlayer增加repeat和uuid属性。

再增加一个业务类GameMusicEffectsDatasource 来管理业务逻辑，存储每种类型的音乐uuid.

这样代码逻辑及可读性大大增加了。

////  AVAudioCustomPlayer.swift//  DropProjectsGame////  Created by lin kang on 17/2/3.//  Copyright © 2017年 lin kang. All rights reserved.//import UIKitimport AVFoundationclass AVAudioCustomPlayer: AVAudioPlayer {    var audioRepeat:Bool = false    var uuid:String?}

////  AudioPlayer.swift//  DropProjectsGame////  Created by lin kang on 17/1/29.//  Copyright © 2017年 lin kang. All rights reserved.//import UIKitimport AVFoundation//笔记，将功能和业务分开//新建数组或字典class AudioHandler: NSObject,AVAudioPlayerDelegate {    var audioPlayers:[String: AVAudioCustomPlayer] = [String: AVAudioCustomPlayer]()        func playSoundWithSoundType(path:String, kRepeat:Bool) ->String?  {    let url = URL(fileURLWithPath: path)        do {            let sound = try AVAudioCustomPlayer(contentsOf: url)            sound.audioRepeat = kRepeat            sound.delegate = self;            sound.play()            let playerKey = String.getUUID()            sound.uuid = playerKey            audioPlayers[playerKey] = sound            return playerKey        } catch{            print("\(path) 不能播放!")        }        return nil    }        func stopSoundWithSoundType(soundID:String) {        let audioPlayer = audioPlayers[soundID]        audioPlayer?.stop();    }        public func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool)    {        let customPlayer:AVAudioCustomPlayer = player as! AVAudioCustomPlayer        //音乐循环播放        if customPlayer.audioRepeat{            player.play()        }else{            player.stop()            audioPlayers.removeValue(forKey:customPlayer.uuid!)        }    }        /* if an error occurs while decoding it will be reported to the delegate. */     public func audioPlayerDecodeErrorDidOccur(_ player: AVAudioPlayer, error: Error?)     {}}

////  GameMusicEffectsDatasource.swift//  DropProjectsGame////  Created by lin kang on 17/2/3.//  Copyright © 2017年 lin kang. All rights reserved.//import UIKitenum GameAudioType{    case backround_one,    backround_two,    backround_three,    backround_four,    collison,    fallingon,    gameOver,    gameWin        func getStateMusicName() -> String! {        switch self {        case .backround_one:            return "backGroundMusic_1.mp3";        case .backround_two:            return "backGroundMusic_2.mp3"        case .backround_three:            return "backGroundMusic_3.mp3"        case .backround_four:            return "backGroundMusic_4.mp3"        case .collison:            return "collision.wav"        case .fallingon:            return "fallingOn.mp3"        case .gameOver:            return "gameOver.wav"        case .gameWin:            return "gameWin.wav"        }    }}class GameMusicEffectsDatasource: NSObject {    let audioHandler:AudioHandler = AudioHandler()    var musicIDs:[String:String] = [String:String]()        func playMusic(musicType:GameAudioType)  {        let soundName = musicType.getStateMusicName()        let path = Bundle.main.path(forResource: soundName, ofType: nil)        var kRepeat:Bool = false        if  (musicType == .backround_one            || musicType == .backround_two            || musicType == .backround_three            || musicType == .backround_four){            kRepeat = true        }        if (path != nil){           let uuid =  audioHandler.playSoundWithSoundType(path: path! as String, kRepeat: kRepeat)            if uuid != nil{                musicIDs[musicType.getStateMusicName()] = uuid            }        }        else{            print("不存在音乐文件\(soundName)")        }    }        func stopMusic(musicType:GameAudioType) {        let uuid = musicIDs[musicType.getStateMusicName()]        audioHandler.stopSoundWithSoundType(soundID: uuid!)    }}