無法讀取undefine的屬性…，位於Object.callbackFromNative在angular 2中

Question

我有一個流代碼

declare var Speech: any;
    export class Lesson implements OnInit {
       text = '';
       constructor()
{
this.text = 'hh';
}
ToSpeech(){
  Speech.listen(this.listenSucess);
}
listenSucess(result){
this.text = reuslt;
}

文件Speech.js

var Speech= (function () {
return {
   listen:funtion(sucess){
      window.plugins.speechRecognition.startListening(function (result) {
          success(result);
      }
   }
}

我有一個錯誤，如：

Cannot read property 'this.text' of undefined 
at Object.callbackFromNative

我將回調用於此功能，謝謝。

Answer 1

您是否嘗試過胖箭頭=>而不是function ？ 因為this在function內部無法訪問

var Speech = (() => {
return {
   listen = (success) => {
      window.plugins.speechRecognition.startListening((result) => {
          success(result);
      }
   }
}