原文：https://medium.com/@lopesgon/translate-angular-4-with-ngx-translate-and-multiple-modules-7d9f0252f139

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I wanted to do a short story to briefly explain to those who are not familiar with ngx-translate in Angular 4 applications, as I was few minutes ago and managed to fix my issue.

Most of the time you only need to use the app.module.ts for a small application but usually, apps grow and new modules appear by the way. I will go to the point in a multiple module implementation of the ngx-translatelibrary.

Your app.module.ts should import:

import { HttpClientModule, HttpClient } from '@angular/common/http';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

Then, you need export your loader function (insert your own path to your i18n assets):

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

Once those done, simply add in NgModules Imports:

imports: [
  HttpClientModule,
  TranslateModule.forRoot({
    loader: {
      provide: TranslateLoader,
      useFactory: (createTranslateLoader),
      deps: [HttpClient],
    }
  })
],

Once your app.module.ts configured with ngx-translate, let’s implement it into your other modules. For this, I strongly recommend to use a shared.module as mentioned in ngx-translate repository, then you don’t need to worry about importing TranslateModule everytime. You only need to add this in your shared.module:

import { NgModule } from '@angular/core';
import { TranslateModule } from '@ngx-translate/core';

@NgModule({
  exports: [
    TranslateModule,
  ]
})

export class SharedModule { }

You are now ready! Just import your shared.module in your other modules:

import { NgModule } from '@angular/core';
import { SharedModule } from '../shared.module';

import { AnotherComponent } from './home.component';

@NgModule({
  declarations: [
    AnotherComponent
  ],
  imports: [
    SharedModule
  ]
})

export class AnotherModule { }

and add the TranslateService in the constructor of your module components, just like this:

import { Component } from '@angular/core';
import { TranslateService } from '@ngx-translate/core';

@Component({
  selector: 'app-home',
  templateUrl: './another.component.html',
})

export class AnotherComponent {
  constructor(public translate: TranslateService) { }
}

Not a big deal nah? Strongly recommend to go through ngx-translate/corerepository which has a good documentation (this story is a simple app real example of the implementation).