vue+axios+element ui 实现全局loading加载示例

import axios from 'axios';

import { Message, Loading } from 'element-ui';

import Cookies from 'js-cookie';

import router from '@/router/index'

let loading  //定义loading变量

function startLoading() { //使用Element loading-start 方法
 loading = Loading.service({
  lock: true,
  text: '加载中……',
  background: 'rgba(0, 0, 0, 0.7)'
 })
}
function endLoading() { //使用Element loading-close 方法
 loading.close()
}
//那么 showFullScreenLoading() tryHideFullScreenLoading() 要干的事儿就是将同一时刻的请求合并。
//声明一个变量 needLoadingRequestCount，每次调用showFullScreenLoading方法 needLoadingRequestCount + 1。
//调用tryHideFullScreenLoading()方法，needLoadingRequestCount - 1。needLoadingRequestCount为 0 时，结束 loading。
let needLoadingRequestCount = 0
export function showFullScreenLoading() {
 if (needLoadingRequestCount === 0) {
  startLoading()
 }
 needLoadingRequestCount++
}

export function tryHideFullScreenLoading() {
 if (needLoadingRequestCount <= 0) return
 needLoadingRequestCount--
 if (needLoadingRequestCount === 0) {
  endLoading()
 }
}

//http request 拦截器
axios.interceptors.request.use(
 config => {
  var token = ''
  if(typeof Cookies.get('user') === 'undefined'){
   //此时为空
  }else {
   token = JSON.parse(Cookies.get('user')).token
  }//注意使用的时候需要引入cookie方法，推荐js-cookie
  config.data = JSON.stringify(config.data);
  config.headers = {
   'Content-Type':'application/json'
  }
  if(token != ''){
   config.headers.token = token;
  }
  showFullScreenLoading()
  return config;
 },
 error => {
  return Promise.reject(err);
 }
);


//http response 拦截器
axios.interceptors.response.use(
 response => {
  //当返回信息为未登录或者登录失效的时候重定向为登录页面
  if(response.data.code == 'W_100004' || response.data.message == '用户未登录或登录超时，请登录！'){
   router.push({
    path:"/",
    querry:{redirect:router.currentRoute.fullPath}//从哪个页面跳转
   })
  }
  tryHideFullScreenLoading()
  return response;
 },
 error => {
  return Promise.reject(error)
 }
)