使用swift 2.0代码Xcode 7.1 IOS 9.1播放嵌入式声音

Question

Copied and Pasted this code principally. Compiles and runs, but plays nothing. Using Xcode 7.1 and IOS 9.1. What have I missed... Loaded sound file into main program and AVAssets...

import UIKit
import AVFoundation

class ViewController: UIViewController {

   var buttonBeep : AVAudioPlayer?

   override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    buttonBeep = setupAudioPlayerWithFile("hotel_transylvania2", type:"mp3")
    //buttonBeep?.volume = 0.9
    buttonBeep?.play()
   }

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func setupAudioPlayerWithFile(file:NSString, type:NSString) -> AVAudioPlayer?  {
    //1
    let path = NSBundle.mainBundle().pathForResource(file as String, ofType: type as String)
    let url = NSURL.fileURLWithPath(path!)

    //2
    var audioPlayer:AVAudioPlayer?

    // 3
    do {
        try audioPlayer? = AVAudioPlayer(contentsOfURL: url)
    } catch {
        print("Player not available")
    }

    return audioPlayer
}



}

Answer 1

You've got this line backwards:

try audioPlayer? = AVAudioPlayer(contentsOfURL: url)

It should be:

audioPlayer = try AVAudioPlayer(contentsOfURL: url)

Side note: the conversion to and from NSString is not necessary here, just use String - and you should not force unwrap the result of NSBundle:

func setupAudioPlayerWithFile(file:String, type:String) -> AVAudioPlayer?  {
    //1
    guard let path = NSBundle.mainBundle().pathForResource(file, ofType: type) else {
        return nil
    }
    let url = NSURL.fileURLWithPath(path)

    //2
    var audioPlayer:AVAudioPlayer?

    // 3
    do {
        audioPlayer = try AVAudioPlayer(contentsOfURL: url)
    } catch {
        print("Player not available")
    }

    return audioPlayer
}