Swift 中的 AudioToolBox - 声音在模拟器中有效，但在我的 iPad 上无效

Question

I'm creating a music app where different chimes will be played at different points in a rhythm cycle. So far, my code works fine in the Simulator but I'm not getting any sound on my device. I get sounds from other apps. Is there something wrong with my code? Thanks for you help!

import UIKit
import AudioToolbox

func playChime1() {
    var chime1URL: NSURL?
    var chime1ID:SystemSoundID = 0
    let filePath = NSBundle.mainBundle().pathForResource("Chime", ofType: "mp3")
    chime1URL = NSURL(fileURLWithPath: filePath!)
    AudioServicesCreateSystemSoundID(chime1URL!, &chime1ID)
    AudioServicesPlaySystemSound(chime1ID)
}
func playChime2() {
    var chime2URL: NSURL?
    var chime2ID:SystemSoundID = 0
    let filePath = NSBundle.mainBundle().pathForResource("Chime2", ofType: "mp3")
    chime2URL = NSURL(fileURLWithPath: filePath!)
    AudioServicesCreateSystemSoundID(chime2URL!, &chime2ID)
    AudioServicesPlaySystemSound(chime2ID)
}
func playChime3() {
    var chime3URL: NSURL?
    var chime3ID:SystemSoundID = 0
    let filePath = NSBundle.mainBundle().pathForResource("Chime3", ofType: "mp3")
    chime3URL = NSURL(fileURLWithPath: filePath!)
    AudioServicesCreateSystemSoundID(chime3URL!, &chime3ID)
    AudioServicesPlaySystemSound(chime3ID)
}

Answer 1

I had the same issue and realised my iPhone was on silent mode, taking it off silent played the sounds.

Unfortunately AudioToolbox sounds respond to the 'Ringer' volume of the device, and not the 'Volume' setting that audio through AVFoundation uses.

It makes sense, as AudioToolbox is supposed to be used for system sounds.

Answer 2

From related question: AudioServicesPlaySystemSound not working on iPad device

You can't play MP3 on iDevice, need to use a different framework.

Answer 3

我的问题是为 AudioQueue 分配的缓冲区数，我分配了 3 个，它在 MacOS 上工作，但是对于 iOS 设备，您至少需要 4 个