为什么在Angular 2中捕获一个Observable后finally()不起作用？

Question

我试图在每个以Angular 2结尾的请求中添加一个加载微调器,所以我扩展了Http服务,调用它为HttpService.在每个请求之后,我想在捕获错误后调用finally()函数,以便我可以停止加载微调器.

但是打字稿说:

[ts]属性'finally'在'Observable'类型中不存在.

import { AuthService } from './../../auth/auth.service';
import { Injectable } from '@angular/core';
import { Http, XHRBackend, RequestOptions, RequestOptionsArgs, Request, Response, Headers } from '@angular/http';

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
import 'rxjs/add/observable/throw';

@Injectable()
export class HttpService extends Http {

    constructor(
        backend: XHRBackend,
        options: RequestOptions,
        private authservice: AuthService
    ) {
        super(backend, options);
        this.updateHeaders(options.headers);
    }

    request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
        return super.request(url, options)
            .catch((response: Response) => this.authError(response))
            .finally(() => {
                // ...
                /* Do something here when request is done. For example
                finish a spinning loader. */
            });
    }

    private authError(response: Response) {
        if (response.status === 401 || response.status === 403) {
            this.authservice.logout();
        }
        return Observable.throw(response);
    }

    private updateHeaders(headers: Headers) {
        headers.set('Content-Type', 'application/json');
        if (this.authservice.isloggedIn()) {
            headers.set('Authorization', `Bearer ${this.authservice.getToken()}`);
        }        
    }
}

如何在每个http请求之后运行一些代码？这样做的最佳方式是什么？

Answer 1

你忘了导入它:

import 'rxjs/add/operator/finally';

Answer 2

抬起头来,未来的读者:

由于角度为6,引入了rxjs版本6.0,我们现在使用finalize而不是finally.

它现在在管道中使用,所以

observable.finally( x => console.log(x)).subscribe()

就是现在

observable().pipe( finalize( x => console.log(x))).subscribe()

然后从中导入 rxjs/operators

import { finalize } from 'rxjs/operators'