Angular HttpClient不发送标头

Question

这是我的代码:

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

---

logIn(username: string, password: string) {
    const url = 'http://server.com/index.php';
    const body = JSON.stringify({username: username,
                                 password: password});
    const headers = new HttpHeaders();
    headers.set('Content-Type', 'application/json; charset=utf-8');
    this.http.post(url, body, {headers: headers}).subscribe(
        (data) => {
            console.log(data);
        },
        (err: HttpErrorResponse) => {
            if (err.error instanceof Error) {
                console.log('Client-side error occured.');
            } else {
                console.log('Server-side error occured.');
            }
        }
    );
}

在这里网络调试:

Request Method:POST
Status Code:200 OK
Accept:application/json, text/plain, */*
Accept-Encoding:gzip, deflate
Accept-Language:en-US,en;q=0.8
Cache-Control:no-cache
Connection:keep-alive
Content-Length:46
Content-Type:text/plain

和数据存储在"请求有效负载"中,但在我的服务器中没有收到POST值:

print_r($_POST);
Array
(
)

我相信错误来自POST期间没有设置的标题,我做了什么错了？

Answer 1

新HttpHeader类的实例是不可变对象.调用类方法将返回一个新实例作为结果.基本上,您需要执行以下操作:

let headers = new HttpHeaders();
headers = headers.set('Content-Type', 'application/json; charset=utf-8');

要么

const headers = new HttpHeaders({'Content-Type':'application/json; charset=utf-8'});

更新:添加多个标头

let headers = new HttpHeaders();
headers = headers.set('h1', 'v1').set('h2','v2');

要么

const headers = new HttpHeaders({'h1':'v1','h2':'v2'});

更新:接受HttpClient标头和参数的对象映射

由于5.0.0-beta.6现在可以跳过HttpHeaders对象的创建,因此直接将对象映射作为参数传递.所以现在可以做到以下几点:

http.get('someurl',{
   headers: {'header1':'value1','header2':'value2'}
});

Answer 2

要添加多个参数或标题,您可以执行以下操作:

constructor(private _http: HttpClient) {}

//....

const url = `${environment.APP_API}/api/request`;

let headers = new HttpHeaders().set('header1', hvalue1); // create header object
headers = headers.append('header2', hvalue2); // add a new header, creating a new object
headers = headers.append('header3', hvalue3); // add another header

let params = new HttpParams().set('param1', value1); // create params object
params = params.append('param2', value2); // add a new param, creating a new object
params = params.append('param3', value3); // add another param 

return this._http.get<any[]>(url, { headers: headers, params: params })

Answer 3

在http请求中设置如下所示的http标头

return this.http.get(url, { headers: new HttpHeaders({'Authorization': 'Bearer ' + token})
 });

Answer 4

我为此挣扎了很长时间。我正在使用 Angular 6，我发现

let headers = new HttpHeaders();
headers = headers.append('key', 'value');

不工作。但什么起作用了

let headers = new HttpHeaders().append('key', 'value');

确实，当您意识到它们是不可变的时，这是有道理的。因此，创建了一个标题后，您无法添加到它。我没试过，但我怀疑

let headers = new HttpHeaders();
let headers1 = headers.append('key', 'value');

也会工作。

Answer 5

我使用的是 Angular 8，唯一对我有用的是：

  getCustomHeaders(): HttpHeaders {
    const headers = new HttpHeaders()
      .set('Content-Type', 'application/json')
      .set('Api-Key', 'xxx');
    return headers;
  }

Answer 6

在手册（https://angular.io/guide/http）中，我读到： HttpHeaders 类是不可变的，因此每个 set() 返回一个新实例并应用更改。

以下代码适用于 angular-4：

return this.http.get(url, {headers: new HttpHeaders().set('UserEmail', email ) });

Answer 7

首先，您需要使用 HttpClient 添加 HttpHeaders

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

你的构造函数应该是这样的。

constructor(private http: HttpClient) { }

那么你可以这样使用

   let header = new HttpHeaders({ "Authorization": "Bearer "+token});

   const requestOptions = {  headers: header};                                                                                                                                                                            

    return this.http.get<any>(url, requestOptions)
        .toPromise()
        .then(data=> {
            //...
            return data;
    });