我一直试图让我的推子来调整 tts “live”的音量，但我做不到。我只能在文本第一次开始时设置音量。无论如何要这样做？
更新：我能够使用对我的视图控制器的以下更改来访问委托：
protocol theSpeechSynth {
func theSpeechSynthVar() -> AVSpeechSynthesizer
}
class GameViewController: UIViewController, theSpeechSynth, AVSpeechSynthesizerDelegate {
let theSpeechSynthesizer = AVSpeechSynthesizer()
func theSpeechSynthVar() -> AVSpeechSynthesizer {
return theSpeechSynthesizer
}
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer,
willSpeakRangeOfSpeechString characterRange: NSRange,
utterance: AVSpeechUtterance) {
print(utterance.volume)
utterance.volume = 1.0
print(utterance.volume)
}
func viewDidLoad() {
super.viewDidLoad()
tts.speechSynthesizer = theSpeechSynthVar()
...
}
}
import AVFoundation
class announceIt {
let voice = AVSpeechSynthesisVoice(identifier: AVSpeechSynthesisVoiceIdentifierAlex)
let speechSynthesizer = AVSpeechSynthesizer()
let voiceToUse = AVSpeechSynthesisVoice(language: "en-GB")
var speechUtterance: AVSpeechUtterance = AVSpeechUtterance()
func speak(speakIt: String) {
speechUtterance = AVSpeechUtterance(string: speakIt)
speechUtterance.voice = voiceToUse
// theVolumes.voice is constantly being updated by the fader
speechUtterance.volume = 0.5
speechSynthesizer.speak(speechUtterance)
}
func volumeChange() {
speechUtterance.volume = Float( theVolumes.voice )
}
}
调用它只是：
let tts: AnnounceIt = AnnounceIt()
// I added this for the delegate:
tts.speechSynthesizer = theSpeechSynthesizer // from the ViewController
tts.speak(speakIt: "I want this volume to go up and down when the volume changes but I can't get it do to that, it will only be the volume when it starts.")
它打印：
0.5
1.0
1.0
1.0
1.0
1.0
...
音量没有增加......这不是话语的完整实现。