Bootstrapping Providers
The bootstrap process also starts the dependency injection system in Angular.We won't go over Angular's dependency injection system here - that is covered later.Instead let's take a look at an example of how to bootstrap your application with application-wide providers.
For this, we will register a service called GreeterService
with the providers
property of the module we are using to bootstrap the application.
app/app.module.ts
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } '@angular/core';
import { AppComponent } from './app.component'
import { GreeterService } from './greeter.service';
@NgModule({
imports: [BrowserModule],
providers: [GreeterService],
declarations: [AppComponent],
bootstrap: [AppComponent]
})
export class AppModule { }
原文: https://angular-2-training-book.rangle.io/handout/bootstrapping/bootstrapping_providers.html