Angular 9：注入惰性加载服务时的拦截器循环依赖性

Question

在将我的延迟加载的服务注入拦截器时，我遇到Cannot instantiate cyclic dependency! InjectionToken HTTP_INTERCEPTORS错误。

但是，很奇怪，我的问题是通过在拦截器的服务注入中添加空的setTimeout(()来解决的。我想知道为什么会这样...

延迟加载的LanguageService：

import { HttpClient } from '@angular/common/http';
@Injectable()

export class LanguageService {

  constructor(private http: HttpClient,
    private _translate: TranslateService) {
    this.getLanguages();
  }
// ....

<：

import { Injectable, Injector } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler } from '@angular/common/http';
import { LanguageService } from '../app/blog/services/language.service';

@Injectable()

export class LanguageInterceptor implements HttpInterceptor {
    private _languageService:LanguageService;

    constructor(private injector: Injector) {
        /*  This way Works!
            setTimeout(() => {
            this._languageService = this.injector.get(LanguageService)
         })*/

         setTimeout(() => {
            this._languageService = this.injector.get(LanguageService)
         })
    }

    intercept(req: HttpRequest<any>, next: HttpHandler) {

拦截桶] ::

import { HTTP_INTERCEPTORS } from '@angular/common/http';
import { LanguageInterceptor } from './lang-interceptor';

export const httpInterceptorProviders = [
  { provide: HTTP_INTERCEPTORS, useClass: LanguageInterceptor, multi: true }
];

<< [共享模块

import { NgModule } from '@angular/core';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';
import { HttpClient, HttpClientModule, HttpClientJsonpModule } from '@angular/common/http';
import { CommonModule } from '@angular/common';
import { RouterModule } from '@angular/router';
import { httpInterceptorProviders } from 'src/utilities/interceptor-barrel';
import { ShareModule } from '@ngx-share/core';
import { FormsModule, ReactiveFormsModule }   from '@angular/forms';

export function HttpLoaderFactory(http: HttpClient) {
    return new TranslateHttpLoader(http, '../assets/i18n/', '.json');
}

const MODULES = [
    HttpClientModule,
    HttpClientJsonpModule,
    CommonModule,
    RouterModule,
    ShareModule,
    FormsModule,
    ReactiveFormsModule
];

@NgModule({
    imports: [
        MODULES,
        TranslateModule.forRoot({
            defaultLanguage: 'en',
            loader: {
                provide: TranslateLoader,
                useFactory: (HttpLoaderFactory),
                deps: [HttpClient]
            }
        }),
    ],
    exports: [
        MODULES,
        TranslateModule
    ],
    declarations: [],
    providers: [
        httpInterceptorProviders
    ],
})

<< [延迟加载的模块

：

 // ....
imports: [
        SharedModule
    ]
 // ....
 providers: [
        LanguageService
    ]
我面临无法实例化循环依赖的问题！将我的延迟加载的服务注入到拦截器中时，InjectionToken HTTP_INTERCEPTORS错误。但是，很奇怪，我的问题正在通过...