获取状态代码0 angular HttpClient？

Question

我使用angular 4的HttpClient get方法有一个奇怪的问题。

从后端返回一些自定义错误消息，我应该处理并显示给用户。但是我在控制台中获得了HttpErrorResponse

HttpErrorResponse:
error: ProgressEvent {isTrusted: true, lengthComputable: false, loaded: 0, 
total: 0, type: "error", …}
headers: HttpHeaders {normalizedNames: Map(0), lazyUpdate: null, headers: 
Map(0)}
message: "Http failure response for (unknown url): 0 Unknown Error"
name: "HttpErrorResponse"
ok: false
status: 0
statusText: "Unknown Error"
url: null

我读到了问题here，但没有一个解决方案帮助了我。在浏览器的网络选项卡中，我能够观察到来自服务器的真实响应：

"{\"StatusCode\":400,
  \"ExceptionMessage\":\"Internal Server Error\",
  \"Error\":\"Internal Server Error\",
  \"Errors\": 
  [{\"Code\":\"ValidationError\",\"Message\":\"Custom message here.\"}]}"

网络选项卡中的请求似乎如下：

General: 
Request URL: https://asdfhost:port/5c77a77101ae8643aeeb61e9
Request Method: GET
Status Code: 400 
Remote Address: address
Referrer Policy: no-referrer-when-downgrade

Response Headers:
cache-control: no-cache
content-type: application/json
date: Thu, 28 Feb 2019 09:42:22 GMT
expires: -1
pragma: no-cache
server: Kestrel
status: 400

Request Headers: 
x-correlation-id: 6if123
Provisional headers are shown
Accept: application/json, text/plain, */*
Authorization: Bearer asdfasdftoken
Origin: http://origin
Referer: http://origin/somewhere
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 
(KHTML, like Gecko) Chrome/72.0.3626.119 Safari/537.36

是否有可能自定义错误打破xhr请求？任何帮助将受到高度赞赏。 :)

Answer 1

确实这是一个CORS问题。发生错误时，后端未设置Allow Origin标头。