post 请求用 formdata 没有任何问题
config.headers.Accept = 'multipart/form-data'
config.data = secrecy.toFormData(enryptData)
但是一旦把formdata的设置删掉，立刻跨域。
Access to XMLHttpRequest at ‘http://ip.ip.ip.ip:8004/sys-oauth2/oauth/token’ from origin ‘http://localhost:8080’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: It does not have HTTP ok status.
http.js?b1d0:108 Error: Network Error
at createError (createError.js?2d83:16)
at XMLHttpRequest.handleError (xhr.js?b50d:83)
查了一下发现 formdata 默认允许跨域：https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
The only allowed values for the Content-Type header are:
application/x-www-form-urlencoded
multipart/form-data
text/plain