在做项目时,用到axios,数据用post提交时,老是报错,错误提示为: Access to XMLHttpRequest at 'http://127.0.0.1:3000/api/add' from origin 'http://localhost:8080' has been blocked by CORS policy: Request header field content-type is not allowed by Access-Control-Allow-Headers in
网页请求报错: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. 如图: 跨域问题解决原理 CORS全称Cross-Origin Resource Sharing,中文全称跨域资源共享.它解决跨域问题的原理是通过向http的请求报文和响应报文里面加入相应的标识告诉