javascript - Spotify 网络 API : Uncaught (in promise) TypeError: Cannot read property 'setState' of undefined

Question

我收到未捕获( promise 中)TypeError:无法读取未定义的属性“setState”。我正在尝试使用 this.setState 渲染一些轨道，但仅限于 9 个轨道，想看看是否一切都正确。

这里的代码如下:

import React from 'react';
require('dotenv').config();

// My Steps: //

// 1. Want to fetch for KD Rusha Top Ablums on Spoitify Done
// 2. Limit them to only 9 tracks
// 3. Add play button on top of each track to play 30 sec of the Song


// GO TO SPOTIFY AND GETTING KD RUSHA TOP ABLUMS lIMIT TO 9 SONGS
// WHEN YOU CLICK ON TOP OF THE ABLUMS A PLAY BUTTON ICON WILL SHOW TO INDICATE THAT YOU CAN PLAY 30 SECONDS OF SONG

export default class SpotifyComponent extends React.Component {

constructor(props){
    super(props);
    this.state = {
       artist: null,
    };
}

componentWillMount() {

var request = new Request('https://api.spotify.com/v1/artists/5JLWikpo5DFPqvIRi43v5y/', {
  method: 'GET',
  headers: new Headers({
  'Accept': 'application/json',
  'Content-Type': 'text/plain',
  'Authorization': 'Access Token Here'
  })

});

  fetch(request)// fetch the Spotify date from KD Rusha Account
    .then(function(response){
      var result = response.json()
        this.setState({// State artist albums
          albums: result,
          selectedTrack: [0]
        });

    console.log(this.setState);
    if (response.status >= 400) {
      throw new Error("Bad response from server");
    }
    return response.json();
  });
}

  render(){
    return(
      <ul className="spotify-cantainer">

      </ul>
    );
  }

}

Answer 1

您将需要使用 .bind 或粗箭头语法 => 来声明您的 Promise 回调。