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
})
}