无法在XCode 9中启动AK4 AKPeriodic功能。在“Plucked String”游乐场的以下摘录中，我插入了两条日志消息来帮助识别处理事件。我从未在控制台日志中看到“定期函数启动”消息。我听到的只是一声非常短暂的咔哒声。
let scale = [0, 2, 4, 5, 7, 9, 11, 12]
let performance = AKPeriodicFunction(frequency: playRate) {
print("periodic function startup")
var note = scale.randomElement()
let octave = [2, 3, 4, 5].randomElement() * 12
if random(0, 10) < 1.0 { note += 1 }
if !scale.contains(note % 12) { print("ACCIDENT!") }
let frequency = (note + octave).midiNoteToFrequency()
if random(0, 6) > 1.0 {
pluckedString.trigger(frequency: frequency)
}
}
AudioKit.output = reverb
AudioKit.start(withPeriodicFunctions: performance)
print("AK startup")
performance.start()