尝试传递请求选项时出错答案

【问题标题】：Getting error trying to pass request options尝试传递请求选项时出错
【发布时间】：2018-05-22 00:39:02
【问题描述】：

我有这样的服务：

   import { Injectable } from "@angular/core";
import { Http, Response, Headers, RequestOptions } from "@angular/http";
import "rxjs/add/operator/map";
import { Usuario } from "../_models/usuarios";
import { HttpClient } from "@angular/common/http";
import { Observable } from "rxjs/Observable";
import { User } from "../_models/user.model";


 private serviceUrl = "apiUrl";
  headers = new Headers({
    Authorization:
      "Bearer " + JSON.parse(localStorage.getItem("currentUser")).token,
    "Content-Type": "application/json"
  });
  options = new RequestOptions({ headers: this.headers });

constructor(private http: Http, private httpClient: HttpClient) {}

  getUser(): Observable<User[]> {
    return this.httpClient.get<User[]>(this.serviceUrl);
  }

问题是当我尝试发送选项来获取方法时：

getUser(): Observable<User[]> {
    return this.httpClient.get<User[]>(this.serviceUrl, this.options);
  }

消息：'RequestOptions' 类型的参数不可分配给 '{ headers?: HttpHeaders | 类型的参数{ [标题：字符串]：字符串 |细绳[]; };观察？：“身体”；参数？：Ht...'。种类属性“标题”不兼容。类型 'Headers' 不可分配给类型 'HttpHeaders | { [标题：字符串]：字符串 |细绳[]; }'。类型 'Headers' 不可分配给类型 '{ [header: string]: string |细绳[]; }'。 “标头”类型中缺少索引签名。

我尝试使用 http 而不是 httpClient 来更改它：

 return this.http.get<User[]>(this.serviceUrl, this.options);

但现在我明白了

message: '预期的类型参数为 0，但得到了 1。'

我做错了什么？

【问题讨论】：

标签： angular

【解决方案1】：

您可以使用HttpClient 它来自@angular/common/http，如下所示：

import { Injectable } from "@angular/core";
import { Usuario } from "../_models/usuarios";
import { HttpClient, HttpHeaders } from "@angular/common/http";
import { Observable } from "rxjs";
import { User } from "../_models/user.model";

@Injectable()
export class UserService{
private serviceUrl = "apiUrl";
  headers = new HttpHeaders({
    Authorization: "Bearer " + JSON.parse(localStorage.getItem("currentUser")).token,
    "Content-Type": "application/json"
  });

constructor(private httpClient: HttpClient) {}

  getUser(): Observable<User[]> {
    return this.httpClient.get<User[]>(this.serviceUrl, { 'headers': this.headers});
  }
}

【讨论】：

【解决方案2】：

如果你使用httpClient，你应该

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

httpOptions = {
    headers: new HttpHeaders({
        'Content-Type':  'application/json',
        'Authorization': "Bearer " + JSON.parse(localStorage.getItem("currentUser")).token
    })
}

...

getUser(): Observable<User[]> {
    return this.httpClient.get<User[]>(this.serviceUrl,httpOptions);
}

【讨论】：