axios的使用及API接口的封装

api/config.js

import axios from 'axios'

// 给所有axios请求设置基础的域名
// axios.defaults.baseURL = 'http://localhost:3000'


//用axios.create可以创建axios的实例，允许不同实例有不同配置
const axios1 = axios.create({
    baseURL: 'https://cnodejs.org/api/v1',
    // 请求超时的时间
    timeout: 5000
}); 
// const axios2 = axios.create({
//     baseURL: 'http://www.test.com',
//     timeout: 5000
// });


//添加请求拦截器，会在发起请求之前执行相应的需求
axios1.interceptors.request.use(function (config) {
    // console.log('我是请求拦截器');
    let token = localStorage.getItem("token")
    if (token){
      config.headers.common['Authorization'] = 'Bearer ' + token;
    }
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    return Promise.reject(error);
  });

// //添加响应拦截器，会在返回数据后先执行相应的需求
axios1.interceptors.response.use(function (response) {
    console.log('我是响应拦截器');
    // Do something with response data
    return response;
  }, function (error) {
    // Do something with response error
    console.log('error',error.status);

    return Promise.reject(error);
  });
export default axios1

api/http.js

import axios1 from './config'

//获取主题
export function getTopics(type) {
    return axios1({
        url: '/topics',
        method: 'get',
        data: {
            params: {
                type
            }
        }
    })
}

在组件中调用接口

    async getData(type) {
        try {
            let res = await getTopics(type)
            this.setState({
                list: res.data.data,
                loading: false
            })
        } catch (error) {
            console.log('Request Failed', error);
        }
    }
    componentDidMount() {
        //请求数据
        this.getData('good')
    }

    //切换标签
    toggle(index) {
        this.setState({
            curIndex: index,
            loading: true
        })
        let type = this.state.tabList[index].type
        //请求数据
        this.getData(type)
    }

react devtool的安装和使用

1. 极简插件： https://chrome.zzzmh.cn/
2. 搜"react" 下载 "React Developer Tools 开发工具"
3. 解压后，把*.crx扩展名改为zip,再解压
4. 打开chrome浏览器， 右上角，菜单--> 更多工具 -> 扩展程序 --> 打开"开发者模式" ---> 加载已解压的扩展程序->选择刚才的文件夹即可安装devtools
5. 重启chrome,打开react项目，即可在开发者工具最右侧看到新增的"components"，可查看组件结构和props,state

楼层导航的思路

import React, { Component } from 'react';
import './Elevator.css'
class Elevator extends Component {
    constructor(props) {
        super(props);
        this.state = { 
           
         }
    }
    scroll(){
        console.log(document.documentElement.scrollTop);
    }
    componentDidMount(){
        let floorEl = document.querySelectorAll(".floor")
        this.listHeight = [...floorEl].map(item=>{
            return item.offsetTop
        })
        window.addEventListener("scroll",this.scroll)
    }
    scrollTo(index){
        window.scrollTo({
            behavior: "smooth",
            top: this.listHeight[index]
        })
    }
    render() { 
        return ( 
            <div>
                <button onClick={()=>this.scrollTo(2)}>到达floor3</button>
                <div className="floor">floor1</div>
                <div className="floor">floor2</div>
                <div className="floor">floor3</div>
                <div className="floor">floor4</div>
                <div className="floor">floor5</div>
            </div>
            
         );
    }
}
 
export default Elevator;