添加新字符串时，AVSpeechSynthesizer无法正常工作[xcode - swift 4]

Question

我使用下面的代码随机读取随机句子。然而，当AVSpeechSynthesizer仍然在说出前一个句子而没有说出第二个句子时，我会在调用一个随机句子时遇到问题。我要问的是，在完成第一句话后，怎样才能说出第二句话？

任何进口将不胜感激。干杯

继承我的代码：

import UIKit
import AVFoundation


class ViewController: UIViewController {

var myTimer = Timer()
   let string = ["what kind of car do you have?", "do you like the beach?","did you bring a towel?","There are big waves today"]
var randomTimer = Int()


@objc func speakToMe(){

    let random = Int.random(in: 0...3)
    randomTimer = Int.random(in: 0...2)
    print(randomTimer)
    print(string[random])


let utterance = AVSpeechUtterance(string: string[random])
utterance.voice = AVSpeechSynthesisVoice(language: "en-GB")
utterance.rate = 0.1
let synthesizer = AVSpeechSynthesizer()
synthesizer.speak(utterance)

}

override func viewDidLoad() {
    super.viewDidLoad()
    speakToMe()
    myTimer = Timer.scheduledTimer(timeInterval: TimeInterval(randomTimer), target: self, selector: #selector(ViewController.speakToMe), userInfo: nil, repeats: true)
}


}   

Answer 1

你可以简单地使用AVSpeechSynthesizerDelegate，你可以从你的代码中删除计时器。

要首先使用AVSpeechSynthesizerDelegate，您需要使用AVSpeechSynthesizerDelegate确认您的视图控制器，如下所示：

class ViewController: UIViewController, AVSpeechSynthesizerDelegate {

接下来你需要添加

synthesizer.delegate = self

在你的viewDidLoad方法。你需要申报

let synthesizer = AVSpeechSynthesizer()

方法之外和课堂内部。

你可以使用randomElement属性从string数组中找到随机元素。

你的最终代码如下：

import UIKit
import AVFoundation

class ViewController: UIViewController, AVSpeechSynthesizerDelegate {

    let string = ["what kind of car do you have?", "do you like the beach?","did you bring a towel?","There are big waves today"]
    let synthesizer = AVSpeechSynthesizer()

    override func viewDidLoad() {
        super.viewDidLoad()
        synthesizer.delegate = self
        speakToMe()
    }

    @objc func speakToMe(){

        let utterance = AVSpeechUtterance(string: string.randomElement()!)
        utterance.voice = AVSpeechSynthesisVoice(language: "en-GB")
        utterance.rate = 0.1
        synthesizer.speak(utterance)

    }

    func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
        speakToMe()
    }
}

编辑：

由于你在数组中只使用了4个元素，因此当你为它采用随机字符串时，有可能多次重复相同的句子，这样你就可以在这里再添加一个逻辑来阻止它。

更新您的speakToMe功能，如下所示：

@objc func speakToMe(){

    var randomStr = string.randomElement()!
    while previousStr == randomStr {
        randomStr = string.randomElement()!
    }
    previousStr = randomStr
    let utterance = AVSpeechUtterance(string: randomStr)
    utterance.voice = AVSpeechSynthesisVoice(language: "en-GB")
    utterance.rate = 0.1
    synthesizer.speak(utterance)
}

并在函数外声明var previousStr = ""。