SpeechUtterance不停止

Question

我有一個啓用分頁的集合視圖。我正在使用AVSpeechSynthesizer將文本轉換爲集合視圖的單元格中的語音。當我從一個單元格滑動到另一個單元格時，我希望語音停止。現在我正在調用在單元類中聲明的stopSpeech函數。

//Cell Class 
import UIKit 
import AVFoundation 

class DetailArticleCell: UICollectionViewCell, AVSpeechSynthesizerDelegate { 
    @IBOutlet weak var articleImage: UIImageView! 
    @IBOutlet weak var articleText: UILabel! 
    @IBOutlet weak var textToSpeechBGView: UIVisualEffectView! 
    @IBOutlet weak var textToSpeechButton: UIButton! 
    var isSpeaking: Bool = true 
    let speechSynthesizer = AVSpeechSynthesizer() 
    var speechText: String! 

    override func awakeFromNib() { 
     textToSpeechBGView.layer.cornerRadius = 0.5 * textToSpeechBGView.bounds.size.width 
     textToSpeechBGView.clipsToBounds = true 
     setImageForTextSpeech() 
     speechSynthesizer.delegate = self 

    } 

    func setImageForTextSpeech(){ 
     isSpeaking ? textToSpeechButton.setImage(#imageLiteral(resourceName: "noAudio"), for: .normal) : textToSpeechButton.setImage(#imageLiteral(resourceName: "audio"), for: .normal) 
    } 

    func receive(text: String) -> String{ 
     return text 
    } 
    func speak(text: String){ 
     let speechUtterance = AVSpeechUtterance(string: text) 
     // speechUtterance.rate = 1.0 
     speechSynthesizer.speak(speechUtterance) 
     isSpeaking = false 
    } 
    func stopSpeech(){ 
     speechSynthesizer.stopSpeaking(at: .immediate) 
     isSpeaking = true 
    } 

    func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) { 
     isSpeaking = true 
     setImageForTextSpeech() 
    } 


    @IBAction func textToSpeechAction(_ sender: Any) { 
     print("clicked") 

     if isSpeaking { 
      guard let textContent = speechText else { 
       speak(text: "") 
       return 
      } 
      speak(text: textContent) 

     } else { 
      stopSpeech() 
     } 
     setImageForTextSpeech() 
    } 


} 

然後我調用collectionView的didEndDisplayingCell方法中的函數。

func collectionView(_ collectionView: UICollectionView, didEndDisplaying cell: UICollectionViewCell, forItemAt indexPath: IndexPath) { 

    let cell=collectionView.dequeueReusableCell(withReuseIdentifier: "detailArticleCell", for: indexPath) as! DetailArticleCell 
    cell.stopSpeech() 
} 

這隻適用於每第三個細胞。但是我希望當用戶每次滑動到下一個單元格時都會停止語音。

Answer 1

改變這一行：

let cell=collectionView.dequeueReusableCell(withReuseIdentifier: "detailArticleCell", for: indexPath) as! DetailArticleCell 

到：

if let detailCell = cell as? DetailArticleCell 
{ 
    detailCell.stopSpeech() 
} 

，看看會發生什麼。

該委託方法已經提供了一個參數，不再顯示該單元格，因此不需要調用dequeueReusableCell（這可能會給您帶來意想不到的效果）。