Angular HttpClient返回期望可观察而不是可观察

使用HttpClient时,我在返回类型上遇到编译错误.在我的函数GetPortfolio中,我期待GET调用返回Observable类型的json对象< Portfolio>但它给出了错误：

输入Observable< HttpEvent< Portfolio>>不能分配给Observable< Portfolio>类型.输入HttpEvent< Portfolio>不能分配给类型投资组合.类型HttpProgressEvent不能分配给类型Portfolio. HttpProgressEvent类型中缺少属性名称.

我的代码：

import { Injectable } from '@angular/core';
import { environment } from './environments/environment';
import { HttpClient,HttpHeaders } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';


export interface Portfolio {
  name: string;
  id: string;
}

@Injectable()
export class PortfolioService {

    private httpOptions;

    apiUrl: string;

    constructor(private http: HttpClient) {
      this.apiUrl = environment.apiUrl + "/api/portfolios";

      this.httpOptions = {
        headers: new HttpHeaders(
          {
            'Content-Type': 'application/json',})   
      };
    }


    GetPortfolio(portfolioId: string): Observable<Portfolio> {
      return this.http.get<Portfolio>(this.apiUrl + '/${portfolioId}',this.httpOptions);
   }

}

从角度英雄教程和文档HttpClient请求应该期望Observable< any>：Angular HttpClient doc

我做错了什么？或者我应该将返回值设置为Observable< HttpEvent< Portfolio>> ？

这很奇怪,如果你写的话不要给错误

GetPortfolio(portfolioId: string): Observable<Portfolio> {
    return this.http.get<Portfolio>('....',{
        headers: new HttpHeaders(
            {
                'Content-Type': 'application/json',})   
    });
}

看起来,编译器期望一个对象具有正确的头,参数,观察……,但由于你的对象没有类型,编译器可以接受它

即使你能做到

headers: HttpHeaders = new HttpHeaders({
        'Content-Type': 'application/json',})
GetPortfolio(portfolioId: string): Observable<Portfolio> {
        return this.http.get<Portfolio>('...',{
            headers: this.headers
        })
    }

Angular HttpClient返回期望可观察而不是可观察

猜你在找的Angularjs相关文章