Angular 4不包含HTTP请求的标头

问题描述

我正在尝试非常简单的角度4 http请求.当我检查chrome开发人员工具时，看不到http标头.

I am trying very simple angular 4 http request.When i check chrome developer tools, i couldn't see http headers.

const headers: Headers = new Headers();
headers.append('Content-Type', 'application/json');
headers.append('Authorization', 'Bearer: 123213');
this.http.post('https://127.0.0.1:502', JSON.stringify(token), {headers: headers}).subscribe();

我错过了什么吗?

推荐答案

从[email protected].开始，不推荐使用@angular/http模块的所有类.现在应使用angular/common/http. 在此处阅读以了解更多信息.

Starting with [email protected]. the @angular/http module is deprecated with all its classes. Now angular/common/http should be used. Read here for more.

import { HttpHeaders } from '@angular/common/http';

const httpOptions = {
  headers: new HttpHeaders({
    'Content-Type':  'application/json',
    'Authorization': 'my-auth-token'
  })
};

this.http.post(
   "http://localhost:3000/contacts",
   JSON.stringify({id: 4, name: 'some'}),
   httpOptions
).subscribe();

对于较旧的版本，您可以这样做:

For the older versions, you can do it like this:

import {Http, Headers, RequestOptions} from '@angular/http';

export class AppComponent {
    constructor(private http: Http) {
        const headers = new Headers();
        headers.append('Content-Type', 'application/json');
        headers.append('authentication', `hello`);

       const options = new RequestOptions({headers: headers});
       this.http.post(
           "http://localhost:3000/contacts",
           JSON.stringify({id: 4, name: 'some'}),
           options
       ).subscribe();

您必须确保要从@angular/http导入正确的对象:

You have to ensure that you're importing correct objects from the @angular/http:

import {Http, Headers, RequestOptions} from '@angular/http';

如果仍然看不到标头，则可能是所使用的服务器不允许标头.当浏览器向另一个来源发出请求时，它会发送访问控制标头请求标头，以检查服务器是否允许自定义标头.如果您的服务器未配置为允许自定义标头，则在随后的请求中将看不到它们.

If you still don't see your headers, it's also possible that the server you're using doesn't allow them. When a browser makes a request to the other origin, it sends access-control-headers-request header to check if server allows custom header. If your server is not configured to allow custom headers, you will not see them in the consequent requests.

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