beforeSend 出现跨域问题，header里直接设置token就没问题----Day1

article/2025/11/3 15:15:30

一开始前端调用后端接口出现跨域问题，右键查看元素，会有跨域错误提示，类似下图，后来找后端设置了一下，问题解决。可以登录获取token等参数了。

但是请求设备列表时，beforeSend 中设置token却失败了，没有效果，出错，然后后端程序给的解决方案是在header中设置。

//beforesend这个不行，传不过去beforeSend: function(xhr) {xhr.setRequestHeader("token", window.sessionStorage.getItem("Token"));},

是在header里直接设置token就没问题

 headers: { 'Content-Type': 'application/json;charset=utf8', 'token': window.sessionStorage.getItem("Token") },

layui框架 ajax 调用接口，登录，查询设备记录一下

<!DOCTYPE html>
<html><head><meta charset="utf-8" /><title></title><style>html,body {width: 100%;height: 100%;overflow: hidden;margin: 0;padding: 0;background-color: #062F6B;}</style><script src="../layuiadmin/layui/layui.js"></script><script>layui.use(['form'], function() {var $ = layui.$,form = layui.form;window.setInterval(function() {refreshToken();}, 10 * 60 * 1000); //60*1000 秒  10*60*1000=10分钟 刷新一次token，防止token过期function refreshToken() {$.ajax({type: 'POST',url: '/Login/Account/PhoneLogpwd',data: { "oldToken": window.sessionStorage.getItem("token") },contentType: 'application/json',success: function(result) {alert(JSON.stringify(result));if (result.resultCode == "10000000") {//登录成功console.log(result.data);var token = result.data.token;alert(token);//将生成的token重新放入到session中window.sessionStorage.setItem("token", token);}},error: function(XMLHttpRequest, textStatus, errorThrown) {alert(JSON.stringify(errorThrown))}});}login();function login() {$.ajax({type: 'POST',url: '/Login/AccountPwd',data: { "loginName": "haisen", "loginpwd": "123456" },dataType: "json",success: function(result) {// alert(JSON.stringify(result));if (result.resultCode == "10000000") {//登录成功console.log(result.data);var token = result.data.token;//将token放入到session中window.sessionStorage.setItem("Token", token);}},error: function(XMLHttpRequest, textStatus, errorThrown) {alert(JSON.stringify(errorThrown))}});}getDevices();function getDevices() {$.ajax({type: 'GET',url: '/Device/List',// data: { "address": "" },dataType: 'json',headers: { 'Content-Type': 'application/json;charset=utf8', 'token': window.sessionStorage.getItem("Token") },success: function(result) {alert(result.resultCode);if (result.resultCode == "10000000") {//登录成功//获取设备信息alert("success");console.log(result.data);}},error: function(XMLHttpRequest, textStatus, errorThrown) {alert(2);if (typeof error_callback == "function") {error_callback(errorThrown); //成功后回调函数}}});}});</script>
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