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1.前端代码<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title></head><body> <script> /** * type: get/post * url: http://localhost:3000 http://localhost:3000/details http://localhost:3000/users * data: lid=5 / uname=lili&upwd=123456 * dataType: '' / 'json', 如果服务端返回的是json格式字符串，就通过dataType通知ajax函数自动转换为对象 * **/ ajax({ type: 'get', url: 'http://localhost:3000', dataType: 'json' }) // data 不写在解构时值默认为 data: undefined ajax({ type: 'get', url: 'http://localhost:3000/details', data: 'lid=0', dataType: 'json' }) ajax({ type: 'post', url: 'http://localhost:3000/users', data: 'uname=lili&upwd=123456', }).then(function(res){ alert(res) }) // dataType 不写在解构时值默认为 dataType: undefined function ajax({type, url,data, dataType}){ return new Promise(function(open){ var xhr = new XMLHttpRequest() xhr.onreadystatechange = function(){ if(xhr.readyState === 4 && xhr.status === 200){ if(dataType === 'json'){ var res = JSON.parse(xhr.responseText) }else{ var res = xhr.responseText } console.log(res) open(res) } } if(type === 'get' && data !== undefined){ url += `?${data}` } xhr.open(type, url, true) xhr.setRequestHeader('Content-Type','application/x-www-form-urlencoded') if(type === 'get'){ xhr.send() }else{ xhr.send(data) } }) } </script></body></html>另：ajax实际代码实现如下 <!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title></head><body> <script> var xhr = new XMLHttpRequest() xhr.onreadystatechange = function(){ if(xhr.readyState === 4 && xhr.status === 200){ console.log(xhr.responseText) } } xhr.open('get', 'http://localhost:3000', true) xhr.send() </script></body></html>
2.后端代码1) 创建一个后端项目 
2) 在routes下创建index.js,users.js，代码如下 // index.jsvar express = require('express');var router = express.Router();/* GET home page. */var products = [ { lid:1, pname:'笔记本', price:3400 }, { lid:2, pname:'手机', price:5400 }, { lid:3, pname:'iPad', price:6400 }]router.get('/', function(req, res, next) { res.send(products)});router.get('/details', function(req, res, next){ var lid = req.query.lid res.send(products[lid])})module.exports = router;// user.jsvar express = require('express');var router = express.Router();/* GET users listing. */router.post('/', function(req, res, next) { var uname = req.body.uname var upwd = req.body.upwd if(uname === 'lili' && upwd === '123456'){ res.send('登陆成功') }else{ res.send({ code: 0, message: '用户名或密码错误' }) }});module.exports = router;
3.注：为避免跨域，可将前端代码和后端同时放在一个项目内，使用同一地址，再发送请求调取接口 到此这篇关于利用promise及参数解构封装ajax请求的文章就介绍到这了,更多相关promise封装ajax请求内容请搜索51zixue.net以前的文章或继续浏览下面的相关文章希望大家以后多多支持51zixue.net！
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