如何在Angular2 Ionic2应用程序中设置请求标题

Question

我正在尝试在http中设置请求标题，以获取Ionic2应用程序中的请求。代码的服务部分是

import { Injectable } from '@angular/core';
import { Http, Headers, RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import 'rxjs/add/operator/map';
// model
import { DataModel } from '../models/data.model';
@Injectable()
export class AuthService {
    constructor(private _http: Http){}
    private _url = 'https://sample.com/';
    /**
     * 
     * Request headers to set
     * Accept      : application/json
     * Content-Type: application/json
     * apiKey      : xxx
     * 
    */
    verify(): Observable<DataModel>{ 
        let headers = new Headers()
        headers.append('Accept', 'application/json'); 
        headers.append('Content-Type', 'application/json');
        headers.append('apiKey', 'xxx');
        const requestOptions = new RequestOptions({headers: headers});
        return this._http.get(this._url, requestOptions).map(data => data.json());
    }
}

这是实现请求标头的正确方法。当我在应用程序上尝试此操作时，响应为

XMLHttpRequest cannot load https://testportal.betterplace.co.in/VishwasAPI/api/public/v2/panVerification/BKCPB8852J. 
Response for preflight has invalid HTTP status code 403
EXCEPTION: Response with status: 0  for URL: null

请求/响应

/**
 * Response headers
 */
HTTP/1.1 403 Forbidden
Date: Tue, 14 Mar 2017 08:11:55 GMT
Server: Apache
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, DELETE, PUT
Access-Control-Max-Age: 1000
Access-Control-Allow-Headers: x-requested-with, Content-Type, origin, authorization, accept, client-security-token
Content-Length: 253
Keep-Alive: timeout=15
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1
/**
 * Request headers
 */
OPTIONS xxx HTTP/1.1
Host: xxx
Connection: keep-alive
Access-Control-Request-Method: GET
Origin: http://localhost:8100
User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B143 Safari/601.1
Access-Control-Request-Headers: apikey, content-type
Accept: */*
Referer: http://localhost:8100/
Accept-Encoding: gzip, deflate, sdch, br
Accept-Language: en-GB,en-US;q=0.8,en;q=0.6
AlexaToolbar-ALX_NS_PH: AlexaToolbar/alx-4.0.1

但是，当我使用这些请求标头设置的Postman应用程序中尝试此URL时，我会得到适当的响应。

GET /xxx HTTP/1.1
Host: sample.com
Accept: application/json
Content-Type: application/json
apiKey: xxx
Cache-Control: no-cache
Postman-Token: xxx

我被困在这一点上。

Answer 1

我在您的代码中没有看到任何错误。但是您应该尝试此代码。它在我的应用中工作。

 getMethods(url:any) :Observable<Response>{
         let headers = new Headers();
        headers.append('Content-Type', 'application/json');  
        headers.append('x-token', localStorage.getItem('token'));  
      return this.http.get(`${API_URL2+url}`,{headers:headers})
                .map((res:Response)=>{
                         return res.json();})
                .catch((error:any)=>Observable.throw(error)||'server error');
    }

Answer 2

这是CORS（跨域）问题。在发送实际的发布请求之前，您的浏览器（非角）正在发送选项请求。有效地，您的服务器会丢弃未经认证的选项请求（或您的情况下禁止使用403）。请阅读此答案以获取更多信息。

您是否尝试将" content-type"标头设置为"应用程序/x-www-form-urlenCoded"或" multipart/form-data"？我认为将导致浏览器在发送POST请求之前不要发送选项请求。因此，即使您解决了第一个问题（由于缺少OAuth标题），您仍然可能无法发布，因为第二个问题。

您可以通过安装Cordova Whitelist插件来解决CORS问题

您也可以尝试安装Chrome允许控制 - 原孔扩展。