httpClient的oninit和ondestroy方法

Question

在Angular中httpClient方法有没有ngOnit和ngOnDestroy之类的方法？基本上我试图在每次调用 httpClient 时显示微调器并隐藏微调器。

Answer 1

你需要一个拦截器：

只需要创建一个Service，负责设置Loader是否需要显示或隐藏即可。然后从您的拦截器设置此值：

import { Injectable } from "@angular/core";
import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from "@angular/common/http";
import { Observable } from "rxjs";
import { finalize } from "rxjs/operators";

import { LoaderService } from '../services/loader.service';

@Injectable()
export class LoaderInterceptor implements HttpInterceptor {
    constructor(public loaderService: LoaderService) { }
    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        this.loaderService.show();
        return next.handle(req).pipe(
            finalize(() => this.loaderService.hide())
        );
    }
}

Read this article for more ref.

httpClient的oninit和ondestroy方法

httpClient oninit and ondestroy method

httpclient

typescript

angular-services

angular