我只是不知道该怎么做......
我在这里和谷歌搜索，人们谈到了AVSpeechSynthesizerDelegate，但我无法使用它。
我想在演讲结束时准确地运行一个函数。
我怎样才能做到这一点？如果我必须使用代表，我应该怎么做？
我试过这样的方式：
func speechSynthesizer(synthesizer: AVSpeechSynthesizer, didFinishSpeechUtterance utterance: AVSpeechUtterance) {
falando = false
print("FINISHED")
}
这是我在开发人员的文档中找到的功能之一，虽然演讲被告知并且没有打印出来。
我试图把A类：AVSpeechSynthesizerDelegate放进去，然后我会做Speech.delegate = self（Speech是AVSpeechSynthesizer类型的A属性），但是它说A不符合协议NSObjectProtocol。
一旦演讲结束，我怎么能运行一些功能（甚至是印刷品）？
谢谢！
答案 0 :(得分：15)
A does not conform to protocol NSObjectProtocol表示您的类必须从NSObject继承，您可以阅读更多相关信息here。
现在我不知道你的代码是如何构建的，但是这个小例子似乎对我有用。首先是一个包含AVSpeechSynthesizer：
class Speaker: NSObject {
let synth = AVSpeechSynthesizer()
override init() {
super.init()
synth.delegate = self
}
func speak(string: String) {
let utterance = AVSpeechUtterance(string: string)
synth.speakUtterance(utterance)
}
}
请注意，我在这里设置了委托（在init方法中）并注意它必须从NSObject继承以保持编译器满意（非常重要！）
然后是实际的委托方法：
extension Speaker: AVSpeechSynthesizerDelegate {
func speechSynthesizer(synthesizer: AVSpeechSynthesizer, didFinishSpeechUtterance utterance: AVSpeechUtterance) {
print("all done")
}
}
最后，我可以在这里使用那个类，如下：
class ViewController: UIViewController {
let speaker = Speaker()
@IBAction func buttonTapped(sender: UIButton) {
speaker.speak("Hello world")
}
}
哪个奖励我
当全部完成
AVSpeechSynthesizer停止说话时，在我的控制台中。
希望对你有所帮助。
所以，时间过去了，@ case-silva在下面的评论中询问是否有一个实际的例子，@ dima-gershman建议直接在AVSpeectSynthesizer中使用ViewController。
为了适应这两种情况，我在此处制作了一个简单的ViewController示例UITextField和UIButton。
流程是：
以下是它的外观
UIViewController示例import UIKit
import AVFoundation
class ViewController: UIViewController {
//MARK: Outlets
@IBOutlet weak var textField: UITextField!
@IBOutlet weak var speakButton: UIButton!
let synth = AVSpeechSynthesizer()
override func viewDidLoad() {
super.viewDidLoad()
synth.delegate = self
}
@IBAction func speakButtonTapped(_ sender: UIButton) {
//We're ready to start speaking, disable UI while we're speaking
view.backgroundColor = .darkGray
speakButton.isEnabled = false
let inputText = textField.text ?? ""
let textToSpeak = inputText.isEmpty ? "Please enter some text" : inputText
let speakUtterance = AVSpeechUtterance(string: textToSpeak)
synth.speak(speakUtterance)
}
}
extension ViewController: AVSpeechSynthesizerDelegate {
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
//Speaking is done, enable speech UI for next round
speakButton.isEnabled = true
view.backgroundColor = .lightGray
textField.text = ""
}
}
希望能给你一个线索案例。
答案 1 :(得分：1)
函数viewDidAppear仅作为示例，可以根据需要将相同的代码放置在任何位置：
class MyViewController: UIViewController, AVSpeechSynthesizerDelegate {
var synth = AVSpeechSynthesizer()
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
// make sure to set the delegate before "speaking"
synth.delegate = self
let utterance = AVSpeechUtterance(string: "Hello world!")
synth.speak(utterance)
}
// will be called when speech did finish
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
// do something useful here ...
}
}
答案 2 :(得分：1)
创建一个继承自 NSObject 和 ObservableObject 的 Speaker 类。
internal class Speaker: NSObject, ObservableObject {
internal var errorDescription: String? = nil
private let synthesizer: AVSpeechSynthesizer = AVSpeechSynthesizer()
@Published var isSpeaking: Bool = false
@Published var isShowingSpeakingErrorAlert: Bool = false
override init() {
super.init()
self.synthesizer.delegate = self
}
internal func speak(_ text: String, language: String) {
do {
let utterance = AVSpeechUtterance(string: text)
utterance.voice = AVSpeechSynthesisVoice(language: language)
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)
try AVAudioSession.sharedInstance().setActive(true)
self.synthesizer.speak(utterance)
} catch let error {
self.errorDescription = error.localizedDescription
isShowingSpeakingErrorAlert.toggle()
}
}
internal func stop() {
self.synthesizer.stopSpeaking(at: .immediate)
}
}
扩展它并实现必要的委托方法。
extension Speaker: AVSpeechSynthesizerDelegate {
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didStart utterance: AVSpeechUtterance) {
self.isSpeaking = true
}
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didCancel utterance: AVSpeechUtterance) {
self.isSpeaking = false
try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
}
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
self.isSpeaking = false
try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
}
}
使用 StateObject 包装器将 Speaker 添加到必要的视图中。
struct ContentView: View {
let text: String = "Hello World!"
@StateObject var speaker: Speaker = Speaker()
var body: some View {
HStack {
Text(text)
Spacer()
Button(action: {
if self.speaker.isSpeaking {
speaker.stop()
} else {
speaker.speak(text, language: "en-US")
}
}) {
Image(systemName: self.speaker.isSpeaking ? "stop.circle" : "speaker.wave.2.circle")
.resizable()
.frame(width: 30, height: 30)
}
.buttonStyle(BorderlessButtonStyle())
.alert(isPresented: $speaker.isShowingSpeakingErrorAlert) {
Alert(title: Text("Pronunciation error", comment: "Pronunciation error alert title."), message: Text(speaker.errorDescription ?? ""))
}
}
.padding()
}
}
答案 3 :(得分：0)
// import AVFoundation
import AVFoundation
// Adhere to AVSpeechSynthesizerDelegate
class GetDirectionsViewController: UIViewController, AVSpeechSynthesizerDelegate {
// define a speech session
let speechsynthesizer = AVSpeechSynthesizer()
// set the delegate
speechsynthesizer.delegate = self
// Implement didFinish.
// This is called when speechsynthesizer completes speech
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
print("Speech finished")
}
// Done!