Question

我很困惑：我经常在其他服务中注入并使用我的LoggingService，它可以正常工作。这是我非常简单的LoggingService：

import { Injectable } from '@angular/core';

@Injectable()
export class LoggingService {
  //[...]  
  logInfo(obj: any) {
    if (this.logging) console.info('[INFO] ' + obj);
  }
}

在下面的课程中，我的注入服务未定义：

interceptor.service.ts

import { LoggingService } from './../logging/logging.service';
import { RequestOptionsArgs, Response } from '@angular/http';
import { Injectable, Injector, OnInit } from '@angular/core';
import { IHttpInterceptor } from '@covalent/http';

@Injectable()
export class InterceptorService implements IHttpInterceptor {

  constructor(private logger: LoggingService) {
    console.log('logger = ' + logger); // UNDEFINED
  }

  onRequest(requestOptions: RequestOptionsArgs): RequestOptionsArgs {
    this.logger.logDebug(requestOptions); // Obviously does not work
    return requestOptions;
  }

  // [...] Other methods
}

app.module.ts

import { InterceptorService } from './services/interceptor/interceptor.service';
import { CovalentHttpModule, IHttpInterceptor } from '@covalent/http';
import { LoggingService } from './services/logging/logging.service';

@NgModule({

  imports: [
    // [...]
    CovalentHttpModule.forRoot({
      interceptors: [{
        interceptor: InterceptorService, paths: ['**'],
      }],
    }),
  ],

  providers: [
    LoggingService,
    InterceptorService,
    // [...]
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

这个班级与其他班级有什么不同（注射有效？

我也尝试使用进样器注入服务：

loggingService : LoggingService;
constructor(private injector: Injector) { }
// [...]
loggingService = this.injector.get(LoggingService);

但它始终未定义。我缺少什么？

IHttpInterceptor类来自以下框架： https://teradata.github.io/covalent/#/components/http

Answer 1

使用Angular 4.3的Httpclient，我最终放弃并编写了自己的拦截器。我遇到的问题可能与Covalent的Interceptor服务和配置有关。

注入的服务未定义，但适用于其他类

1 个答案: