javascript - 我无法在 Reactjs 中 console.log() JSON 数据？

Question

我正在使用 axios 从 api 端点获取数据。我使用 getAllUser() 方法来获取数据，并使用 displayUsers() 来显示数据中的 userName 和 email 。我无法在控制台中获取 JSON 响应。我还在 Chrome 中看到了 XHR，但未向该 API 端点发出请求。请告诉我应该在 getAllUser() 和 displayUsers() 中更改什么，因为我认为我在这些方法中做错了什么。

代码:

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

class App extends Component {

  constructor(props){
    super(props);
    this.state = {
          userList:[]
    }
  }

  ComponentDidMount(){
        if(window.sessionStorage.getItem("ud") !== null){
            var _userData = JSON.parse(window.sessionStorage.getItem("ud"));
            this.userDetails = _userData;
        }
        this.getAllUser();
  }

  getAllUser(){
        axios({
            method:"GET",
            url:"http://62.210.93.54:6010/api/getAllUser",
            auth:{
                username:this.userDetails.email,
                password:this.userDetails.password
            }
        }).then((response)=>{
            console.log(response.data);
            this.setState({
                userList:response.data.results
            })    
        })
  }

  displayUsers(){
        return this.state.userList.map( user => {
          return(
            <div className="item-card">
               <div className="info">    
                    <div className="username">Username: {user.userName}</div>
               </div>
            <div className="del-wrap">
                <img src={require("../../images/cancel.svg")}/>
            </div>
            </div>
            );
        })
  }

  render() {
        return(
          <div className="users-wrap">
                <h1>Users</h1>
                <div className="task-content">
                    <div className="user-wrap">
                        <div className="users">
                            <div className="item-card add">
                                    <img src={require("../../images/plus.svg")} className="plus-icon" />
                                    <div className="lbl">Add a new User</div>
                             </div>

                             {this.displayUsers()}

                        </div>
                    </div>
                </div> 
          </div>
        );
    }
}

export default App;

JSON 响应应该有 4 个对象，模型架构如下所示:

 {
  "results": [
    {
      "createdBy": null,
      "updatedBy": "Ankit",
      "createdDate": 1523892363509,
      "updatedDate": 1524066767311,
      "id": "5ad4c1964417fc66067b29cf",
      "userName": "admin",
      "email": "ankit@woocation.com",
      "roles": [
        "USER"
      ]
    },
    {
      "createdBy": null,
      "updatedBy": null,
      "createdDate": 1523971940177,
      "updatedDate": 1523971940177,
      "id": "5ad5f7640ff4ec580b885a2e",
      "userName": "varun",
      "email": "varun@woocation.com",
      "roles": [
        "ADMIN"
      ]
    },
    {
      "createdBy": null,
      "updatedBy": null,
      "createdDate": 1524302563169,
      "updatedDate": 1524302563169,
      "id": "5adb02e30ff4ec53076ffbb7",
      "userName": "Rahul",
      "email": "rahul@woocation.com",
      "roles": [
        "admin"
      ]
    },
    {
      "createdBy": null,
      "updatedBy": null,
      "createdDate": 1524303894654,
      "updatedDate": 1524303894654,
      "id": "5adb08160ff4ec53076ffbbb",
      "userName": "Nandita",
      "email": "nandita@woocation.com",
      "roles": [
        "member"
      ]
    },
    {
      "createdBy": null,
      "updatedBy": null,
      "createdDate": 1524308787960,
      "updatedDate": 1524308787960,
      "id": "5adb1b330ff4ec53076ffbc2",
      "userName": "user",
      "email": "user@woocation.com",
      "roles": [
        "USER"
      ]
    },
    {
      "createdBy": null,
      "updatedBy": null,
      "createdDate": 1524327504461,
      "updatedDate": 1524327504461,
      "id": "5adb64500ff4ec53076ffbc4",
      "userName": "Rinku",
      "email": "test@woocation.com",
      "roles": [
        "admin"
      ]
    }
  ],
  "httpStatus": "OK",
  "message": "All Users response"
}

Answer 1

看起来您在使用生命周期 Hook 时出现了拼写错误:

componentDidMount() {} 而不是 ComponentDidMount() {}(无大写 C)