React - componentDidMount API 调用不获取数据？答案

【问题标题】：React - componentDidMount API call does not fetch data?React - componentDidMount API 调用不获取数据？
【发布时间】：2016-11-02 09:23:15
【问题描述】：

所以我正在尝试创建这个画廊。我首先对图像的链接进行了硬编码，但现在想通过 API 调用获取图像。我试图实现这一点，但它以某种方式失败了，它仍在从 flickrImages 数组中获取硬编码的图像。有什么建议吗？（顺便说一下，这是来自教程）

import React, {Component} from 'react'

const flickrImages = [
  "https://farm2.staticflickr.com/1553/25266806624_fdd55cecbc.jpg",
  "https://farm2.staticflickr.com/1581/25283151224_50f8da511e.jpg",
  "https://farm2.staticflickr.com/1653/25265109363_f204ea7b54.jpg",
  "https://farm2.staticflickr.com/1571/25911417225_a74c8041b0.jpg",
  "https://farm2.staticflickr.com/1450/25888412766_44745cbca3.jpg"
];

export default class Gallery extends Component {
  constructor(props) {
    super(props);
    this.state = {
      images: flickrImages,
      selectedImage: flickrImages[0]
    }
  }
  componentDidMount() {
    const API_KEY = 'a46a979f39c49975dbdd23b378e6d3d5';
    const API_ENDPOINT = `https://api.flickr.com/services/rest/?method=flickr.interestingness.+getList&api_key=${API_KEY}&format=json&nojsoncallback=1&per_page=5`;

    fetch(API_ENDPOINT).then((response) => {
      return response.json().then((json) => {
        const images = json.photos.photo.map(({farm, server, id, secret}) => {
          return `https://farm${farm}.staticflickr.com/${server}/${id}_${secret}.jpg`
        });
        this.setState({images, selectedImage: images[0]});
      })
    })
  }

  handleThumbClick(selectedImage) {
    this.setState({
      selectedImage
    })
  }

  render() {
    const {images, selectedImage} = this.state;

    return (
      <div className="image-gallery">
        <div className="gallery-image">
          <div>
            <img src={selectedImage} />
          </div>
        </div>
        <div className="image-scroller">
          {images.map((image, index) => (
            <div key={index} onClick={this.handleThumbClick.bind(this,image)}>
              <img src={image}/>
            </div>
          ))}
        </div>
      </div>
    )
  }
}

【问题讨论】：

这是 react-native 还是 react 项目？

标签： javascript api reactjs

【解决方案1】：

API_ENDPOINT 不正确，

flickr.interestingness.+getList&api_key=${API_KEY}

应该是

flickr.interestingness.getList&api_key=${API_KEY}

class Gallery extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      images: [],
    }
  }
  componentDidMount() {
    const API_KEY = 'a46a979f39c49975dbdd23b378e6d3d5';
    const API_ENDPOINT = `https://api.flickr.com/services/rest/?method=flickr.interestingness.getList&api_key=${API_KEY}&format=json&nojsoncallback=1&per_page=5`;

    fetch(API_ENDPOINT).then((response) => {
      return response.json().then((json) => {
        console.log(json);
        const images = json.photos.photo.map(({farm, server, id, secret}) => {
          return `https://farm${farm}.staticflickr.com/${server}/${id}_${secret}.jpg`
        });
        this.setState({images, selectedImage: images[0]});
      })
    })
  }

  handleThumbClick(selectedImage) {
    this.setState({
      selectedImage
    })
  }

  render() {
    const {images, selectedImage} = this.state;

    return (
      <div className="image-gallery">
        <div className="gallery-image">
          <div>
            <img src={selectedImage} />
          </div>
        </div>
        <div className="image-scroller">
          {images.map((image, index) => (
            <div key={index} onClick={this.handleThumbClick.bind(this,image)}>
              <img src={image}/>
            </div>
          ))}
        </div>
      </div>
    )
  }
}

ReactDOM.render(
  <Gallery name="World" />,
  document.getElementById('container')
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="container"></div>

【讨论】：