Question

全部，我在主题新阵营+打字稿。在我的示例代码中，我得到json对象，并将要在控制台上打印一个属性。来自服务器的数据已成功发送。但是，企图使我收到消息输出“的属性‘相册’类型不存在‘从未[]’”，但所有类型的定义。我哪里错了？我应该某种方式初始化的状态“画廊”？

    import React, { Component, Props } from 'react';
import axios from 'axios';


const API = 'http://www.mydomain/testapi/';
const DEFAULT_QUERY = 'test.php';


type Image = {
  id: number,
  name: string,
  title: string,
  date: string,
  size: number
}

type Album = {
  id: number,
  name: string,
  path: string,
  images: Image[]
}


interface State {
 jsonFromServer: string,
 isLoading: boolean,
 errorMsg: string,
 buttonClicked: boolean,
 gallery:Album[]
}


class App extends React.Component {

  state = {
    isLoading: false,
    errorMsg: '',
    buttonClicked: false,
    jsonFromServer: "",
    gallery:[] 
    }

  getInfo() {

    this.setState({ isLoading: true, buttonClicked: true });
    axios.get(API + DEFAULT_QUERY)
      .then(result => this.setState({
        gallery: result.data.gallery,
        isLoading: false,
        jsonFromServer: result.data

      }))
      .catch(error => this.setState({
        errorMsg: error.message,
        isLoading: false
      }));
  }

  render() {
    .....
    if (this.state.buttonClicked) {
      this.state.galerie.length > 0 ? console.log('=>', this.state.gallery.album.id) : '';
    }

 ......
  }
}

export default App;

Answer 1

您定义了private static final String REGEX_FILTER_KEY = "[:]+((?=\\[)\\[[^]]*\\]|(?=\\{)\\{[^\\}]*\\}|\\\"[^\"]*\\\"|(\\d+(\\.\\d+)?))"; List<String> redactKeys = Collections.unmodifiableList(Arrays.asList("username", "password", "userId")); private String redact(@NonNull String responseString) { for (String key : redactingKeys) { Matcher matcher = Pattern.compile(String.format("\"%s\"%s", key, REGEX_FILTER_KEY)).matcher(responseString); if (matcher.find() && matcher.group(1) != null) { responseString = responseString.replace(matcher.group(1), "**********"); } } return responseString; }，但未指定其类型。因此，打字稿将基于初始化来推断state的类型。由于state是一个数组，但没有元素，因此可以推断的最佳和最安全的类型打字稿是galerie

解决方案是注释never[]成员：

state

Answer 2

您的图库是一个数组，并且您试图像对象一样对其进行访问。请尝试以下渲染方法：

  render() {
    .....
    if (this.state.buttonClicked) {
      this.state.galerie.length > 0 ? console.log('=>', this.state.gallery!.album.id) : ''; //it should work now
    }

 ......
  }

类型'never []不存在属性，怎么了？

2 个答案: