Node.js CORS错误，但仅在POST请求时发生，尽管CORS配置（GET无问题）

我使用nodejs express服务器。 尽管允许主机，我仍然有一个CORS错误

“请求的服务器上不存在“访问控制允许来源”标头 资源。”

但仅适用于POST端点。“得到”没有问题。 我的客户端浏览器同时允许（GET和POST）端点：

我的服务器：（正在运行）

客户端（9）：（在本地主机上运行：4200）

知道为什么它不起作用吗

GET的整个请求/响应：

答复：

Referrer Policy: no-referrer-when-downgrade
Access-Control-Allow-Origin: http://localhost:4200
Content-Length: 2
Content-Type: application/json; charset=utf-8
Date: Sun, 14 Jun 2020 14:42:35 GMT
Etag: W/"2-l9Fw4VUO7kr8CvBlt4zaMCqXZ0w"
Server: Cowboy
Vary: Origin
Via: 1.1 vegur
X-Powered-By: Express

Allow: POST
Connection: keep-alive
Content-Length: 4
Content-Type: text/html; charset=utf-8
Date: Sun, 14 Jun 2020 14:30:00 GMT
Etag: W/"4-Yf+Bwwqjx254r+pisuO9HfpJ6FQ"
Server: Cowboy
Via: 1.1 vegur
X-Powered-By: Express

请求：

Accept: application/json, text/plain, */*
Accept-Encoding: gzip, deflate
Accept-Language: en,en-US;q=0.9,fr-FR;q=0.8,fr;q=0.7
Connection: keep-alive
DNT: 1
Host: serverUrl
If-None-Match: W/"2-l9Fw4VUO7kr8CvBlt4zaMCqXZ0w"
Origin: http://localhost:4200
Referer: http://localhost:4200/menu
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

Accept: */*
Accept-Encoding: gzip, deflate
Accept-Language: en,en-US;q=0.9,fr-FR;q=0.8,fr;q=0.7
Access-Control-Request-Headers: content-type
Access-Control-Request-Method: POST
Connection: keep-alive
Host: serverUrl
Origin: http://localhost:4200
Referer: http://localhost:4200/menu
Sec-Fetch-Mode: cors
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

（失败）职位的全部回复/请求 答复：

Allow: POST
Connection: keep-alive
Content-Length: 4
Content-Type: text/html; charset=utf-8
Date: Sun, 14 Jun 2020 14:30:00 GMT
Etag: W/"4-Yf+Bwwqjx254r+pisuO9HfpJ6FQ"
Server: Cowboy
Via: 1.1 vegur
X-Powered-By: Express

请求：

Accept: application/json, text/plain, */*
Accept-Encoding: gzip, deflate
Accept-Language: en,en-US;q=0.9,fr-FR;q=0.8,fr;q=0.7
Connection: keep-alive
DNT: 1
Host: serverUrl
If-None-Match: W/"2-l9Fw4VUO7kr8CvBlt4zaMCqXZ0w"
Origin: http://localhost:4200
Referer: http://localhost:4200/menu
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

Accept: */*
Accept-Encoding: gzip, deflate
Accept-Language: en,en-US;q=0.9,fr-FR;q=0.8,fr;q=0.7
Access-Control-Request-Headers: content-type
Access-Control-Request-Method: POST
Connection: keep-alive
Host: serverUrl
Origin: http://localhost:4200
Referer: http://localhost:4200/menu
Sec-Fetch-Mode: cors
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

尝试为您的路线启用

当需要路由来处理所谓的复杂CORS操作时，必须添加选项路由处理程序。浏览器发送一个额外的请求，一个选项请求

为什么这个特别复杂？因为网络令人毛骨悚然

添加此路由处理程序。就在你的邮件处理之前是一个很好的地方

router.options('/score', cors())

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真管用，谢谢！但我觉得它很难看。有没有什么方法可以自动完成，而不必添加路由器。选择？