如何更新事件处理函数中的类属性？

Question

请帮助您如何访问事件处理函数中的类的属性。

我想在网络语音API的句柄函数中更新类的属性，尽管它总是失败，但我不知道如何将类对象转移到事件处理函数。

以下代码中的错误代码是“无法读取未定义的属性'resultIndex'”

class SpeechToText {
    constructor() {
    this.recognition = null;
    this.text = 'original';
    this.getDataFromRecognition = this.getDataFromRecognition.bind(this);
   }




    getDataFromRecognition(event){
         console.log(this.text);
         var final_transcript = '';
         var interim_transcript = '';
         for (var i = event.resultIndex; i < event.results.length; ++i) {
           if (event.results[i].isFinal) {
             final_transcript += event.results[i][0].transcript;
             console.log('result is Final' + final_transcript);
           } else {    
             interim_transcript += event.results[i][0].transcript;
             console.log('interim transcript' + interim_transcript);
           }
         }
         this.text = final_transcript;

    }

    listening() {
    let recognition = new  window.webkitSpeechRecognition();

    recognition.lang = 'zh-CN';
    recognition.interimResults = false;
    recognition.continuous = false;

    recognition.start();
    recognition.onresult = this.getDataFromRecognition(event);

    recognition.onspeechend = function() {

              this.stop();
            }

    recognition.onnomatch = function(event) {
               console.log( "It is no match.");
            }

    recognition.onerror = function(event) {
              console.log('Error occurred in recognition: ' + event.error);
            }


   }


}

＃

在以下代码中，函数“ this.onresult = function（event）”中的this.text将创建SpeechRecognition的新属性。

class SpeechToText {
    constructor() {
    this.text = 'original';
    this.recognition = null;
   }

   setText(str){
   this.text = str;
   return this.text;
   console.log('this in on setText ' + this);
   }

   getText(){
   return this.text;
   }

    listening() {
    this.recognition = new  window.webkitSpeechRecognition();
    this.recognition.lang = 'zh-CN';
    //this.recognition.lang = 'en-GB';
    this.recognition.interimResults = false;
    this.recognition.continuous = false;

    this.recognition.start();
    console.log("this under class" + this); 
    this.recognition.onresult = function(event) {
               // The SpeechRecognitionEvent results property returns a SpeechRecognitionResultList object
               // The SpeechRecognitionResultList object contains SpeechRecognitionResult objects.
               // It has a getter so it can be accessed like an array
               // The [last] returns the SpeechRecognitionResult at the last position.
               // Each SpeechRecognitionResult object contains SpeechRecognitionAlternative objects that contain individual results.
               // These also have getters so they can be accessed like arrays.
               // The [0] returns the SpeechRecognitionAlternative at position 0.
               // We then return the transcript property of the SpeechRecognitionAlternative object

               this.recognition = new window.webkitSpeechRecognition();
               var final_transcript = '';
               var interim_transcript = '';
               for (var i = event.resultIndex; i < event.results.length; ++i) {
                 if (event.results[i].isFinal) {
                   final_transcript += event.results[i][0].transcript;
                   console.log('result is Final' + final_transcript);
                 } else {    
                   interim_transcript += event.results[i][0].transcript;
                   console.log('interim transcript' + interim_transcript);
                 }
               }

               //_utteranceForEdgeTrigger = final_transcript;
               //final_transcript = capitalize(final_transcript);
               console.log('final_transcript' + final_transcript);
               //this.setText(final_transcript);
               this.text = final_transcript;
               console.log('the text is in listening function :' + this.text);
               console.log('the this in on result is ' + this);
               //window.SpeechToText.getText();



            }


    this.recognition.onspeechend = function() {
              console.log('this in function onspeechend' + this);
              this.stop();
              console.log('speech end')
            }

    this.recognition.onnomatch = function(event) {
               console.log( "I didn't recognise that color.");
            }

    this.recognition.onerror = function(event) {
              console.log('Error occurred in recognition: ' + event.error);
            }


   }


}
var speech = new SpeechToText();
//speech.getbx();
speech.listening();

}