如何获得PDF中的选定单词，以便使该单词发音？ [Swift，PDFKit]

问题描述

我正在Swift中为iOS创建PDF查看器。 通过该应用程序，我想创建一个功能，使学习者可以点击PDF中的每个单词来收听每个单词的发音。

我设法展示了PDF文件并发音了文本。但是，我正在努力将它们连接在一起。

如果您能向我展示如何修改以下代码，以便用户点击单词，然后使用“文字转语音”程序发音该单词，我将不胜感激。

非常感谢您！

ViewController.swift

import UIKit
import PDFKit
import AVFoundation

class ViewController: UIViewController {
    @IBOutlet weak var pdfView: PDFView!

    override func viewDidLoad() {
        super.viewDidLoad()
        if let url = Bundle.main.url(forResource: "pdf",withExtension: "pdf"){
            if let pdfDocument = PDFDocument(url:url){
                pdfView.autoScales = true
                pdfView.document = pdfDocument
                } 
    
let wordTouched = "test"
        //playing the word 
                    let utterance = AVSpeechUtterance(string: wordTouched)
                    utterance.voice = AVSpeechSynthesisVoice(language: "en-US")

                    let synth = AVSpeechSynthesizer()
                    synth.speak(utterance)

我知道有关如何选择PDF（How can I get all text from a PDF in Swift?）中所有文本的讨论很多。 我想得到一个用户点击过的单词，并将其发送到AVSpeechSynthesizer()。

解决方法

1. 将UITapGestureRecognizer添加到pdfView：

   let tapgesture = UITapGestureRecognizer(target: self,action: #selector(tapGesture(_:)))
   pdfView.addGestureRecognizer(tapgesture)
   

2. 轻按手势：

   @objc func tapGesture(_ gestureRecognizer: UITapGestureRecognizer) {
       let point = gestureRecognizer.location(in: pdfView)
   
       if let page = pdfView.page(for: point,nearest: false) {
           //convert point from pdfView coordinate system to page coordinate system
           let convertedPoint = pdfView.convert(point,to: page)
   
           //ensure that there is no link/url at this point
           if page.annotation(at: convertedPoint) == nil {
               //get word at this point
               if let selection = page.selectionForWord(at: convertedPoint) {
                   if let wordTouched = selection.string {
                       //pronounce word
                       let utterance = AVSpeechUtterance(string: wordTouched)
                       utterance.voice = AVSpeechSynthesisVoice(language: "en-US")
   
                       let synth = AVSpeechSynthesizer()
                       synth.speak(utterance)
   
                       //if you also want to show selection of this word for one second
                       pdfView.currentSelection = selection
                       DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
                           self.pdfView.clearSelection()
                       }
                   }
               }
           }
       }
   }