Angular 4 http CORS没有’Access-Control-Allow-Origin’和一个

基本上,如果您要向远程计算机发出请求,例如,运行nginx Web服务器,则可以对同一个应用程序执行所有调用,例如： localhost：4200(默认为angular / cli).然后使用–proxy-config将这些响应重定向到您的服务器.

假设您的服务器的api具有所有/ api前缀入口点.您需要在项目的根目录中创建名为proxy.config.json的文件,并将其配置为：

{
    "/api" : {
        "target" : "http://xx.xxx.xxx.xx",// Your remote address
        "secure" : false,"logLevel" : "debug",// Making Debug Logs in console
        "changeOrigin": true
    }
}

然后,所有的http请求都将指向localhost：4200 / api /.

最后,您应该通过运行ng server –proxy-config proxy.config.json来完成.

如果您发现请求中缺少某些标头,请从您的Web服务器添加它们或编辑您的http.service.ts以附加如下示例：

import { Injectable } from '@angular/core';
import { Http,Headers,RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Rx';
import { isNull } from 'lodash';

@Injectable()
export class HttpClientService {

  private _host: string;
  private _authToken: string;
  private _options: RequestOptions = null;

  constructor(private _http: Http,private _config: AppConfig,private _localStorageService: LocalStorageService) {
      this._host = ''; // Your Host here,get it from a configuration file
      this._authToken = ''; // Your token here,get it from API
  }

  /**
   * @returns {RequestOptions}
   */
   createAuthorizationHeader(): RequestOptions {
      // Just checking is this._options is null using lodash
      if (isNull(this._options)) {
        const headers = new Headers();
        headers.append('Content-Type','application/json; charset=utf-8');
        headers.append('Authorization',this._authToken);
        this._options = new RequestOptions({headers: headers});
      }
      return this._options;
   }

   /**
    * @param url {string}
    * @param data {Object}
    * @return {Observable<any>}
    */
    get(url?: string,data?: Object): Observable<any> {
      const options = this.createAuthorizationHeader();
      return this._http.get(this._host + url,options);
    }

   /**
    * @param url {string}
    * @param data {Object}
    * @return {Observable<any>}
    */
    post(url?: string,data?: Object): Observable<any> {
      const body = JSON.stringify(data);
      const options = this.createAuthorizationHeader();
      return this._http.post(this._host + url,body,options);
    }

}

因此,您可以通过此服务执行所有api调用

import { Component,OnInit } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { HttpClientService } from './http.service.ts';

export class TestComponent implements OnInit {

  _observable: Observable<any> = null;

  constructor(private _http: HttpClientService) { }

  ngOnInit() {
      this._observable = this _http.get('test/')
                .map((response: Response) => console.log(response.json()));
  }

}

Angular 5更新：

在app.module.ts中,您现在需要从’@ angular / http’替换import {HttpModule};使用’@ angular / common / http’中的import {HttpClientModule};

该服务有点变化：

import { Injectable } from '@angular/core';
import { HttpClient,HttpHeaders } from '@angular/common/http';
import { isNull,isUndefined } from 'lodash';

@Injectable()
export class HttpClientService {

  private _host: string;
  private _authToken: string;
  private __headers: HttpHeaders;

  constructor(private _http: HttpClient,get it from API
  }

  /**
   * @returns {HttpHeaders}
   */
   createAuthorizationHeader(): HttpHeaders {
      // Just checking is this._options is null using lodash
      if (isNull(this.__headers)) {
        const headers = new HttpHeaders()
           .set('Content-Type','application/json; charset=utf-8')
           .set('Authorization',this. _authToken || '');
        this.__headers= new RequestOptions({headers: headers});
      }

      return this.__headers;
   }

   /**
    * @param url {string}
    * @param data {Object}
    * @return {Observable<any>}
    */
    get(url?: string,{
          headers : this.createAuthorizationHeader()
      });
    }

   /**
    * @param url {string}
    * @param data {Object}
    * @return {Observable<any>}
    */
    post(url?: string,{
          headers : this.createAuthorizationHeader()
      });
    }
}