AVAudioRecorder和AVAudioPlayer

Question

（1）录音之后无法播放
（2）如何查看真机中录音文件的大小

///////////////初始化
lazy var url:URL = {
       let tmp = NSTemporaryDirectory()
        let path = tmp.appending("aa.caf")
        return URL(fileURLWithPath: path)
    }()
    var recorder:AVAudioRecorder?
    lazy var myplayer:AVAudioPlayer? = {
        let ins = try? AVAudioPlayer(contentsOf: self.url)
        ins?.volume = 1.0
        ins?.numberOfLoops = 0
        ins?.prepareToPlay()
        return ins
    }()
/////////// 录音
@IBAction func btnClick(_ sender: Any) {
        let session = AVAudioSession.sharedInstance()
        try?  session.setCategory(.playAndRecord)
        try? session.setActive(true, options: .notifyOthersOnDeactivation)
        
        
        let dic:[String:Any] = [AVSampleRateKey: NSNumber(floatLiteral: 8000.0),
                   AVFormatIDKey: kAudioFormatLinearPCM,
                   AVNumberOfChannelsKey:NSNumber(1),
                   AVLinearPCMBitDepthKey:NSNumber(8),
                   AVLinearPCMIsFloatKey:true,
                   AVEncoderAudioQualityKey:AVAudioQuality.max]
        
        self.recorder = try? AVAudioRecorder(url: url, settings: dic)
        recorder?.record()
    }

///////////////播放
let result = myplayer.play() //false