<template> <div class="hello"> <button v-on:click="getrs(1)"> 北京 </button> <button v-on:click="getrs(2)"> 上海 </button> </div> </template> <script> let objPromise = {}; export default { name: 'HelloWorld', props: { msg: String }, methods: { getrs(cityId) { this.getCity(cityId).then((data) => { console.log(data); }) }, getCity(cityId) { if(objPromise[cityId]) { /** * 连续第二次调用的话,如果结果还没有回来,返回上个相同请求的promise */ return objPromise[cityId]; } let promise = new Promise((resolve) => { this.axios.get('http://localhost:3000/?cityid='+cityId).then((response)=>{ return response }).catch((response)=>{ return response }).then( (data) => { resolve(data) } ) }) objPromise[cityId] = promise; return promise; } } } </script> <!-- Add "scoped" attribute to limit CSS to this component only --> <style scoped> h3 { margin: 40px 0 0; } ul { list-style-type: none; padding: 0; } li { display: inline-block; margin: 0 10px; } a { color: #42b983; } </style>
2、搭建koa服务
const Koa = require('koa'); const app = new Koa(); app.use(async (ctx, next)=> { ctx.set('Access-Control-Allow-Origin', '*'); ctx.set('Access-Control-Allow-Headers', 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , yourHeaderFeild'); ctx.set('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS'); if (ctx.method == 'OPTIONS') { ctx.body = 200; } else { await next(); } }); app.use(async(ctx)=>{ let url =ctx.url //从request中获取GET请求 let request =ctx.request let req_query = request.query let req_querystring = request.querystring //从上下文中直接获取 let ctx_query = ctx.query let ctx_querystring = ctx.querystring ctx.body={ url, } }) app.listen(3000,()=>{ console.log('server is starting at port 3000'); })