Getting instance of service without constructor injection

Yes, ReflectiveInjector.resolveAndCreate() creates a new and unconnected injector instance.

You can inject Angulars Injector instance and get the desired instance from it using

constructor(private injector:Injector) {  injector.get(MyService);}

You also can store the Injector in some global variable and than use this injector instance to acquire provided instances for example like explained in https://github.com/angular/angular/issues/4112#issuecomment-153811572

In the updated Angular where ngModules are used, you can create a variable available anywhere in the code:
Add this code in app.module.ts

import { Injector, NgModule } from '@angular/core';    export let AppInjector: Injector;        export class AppModule {      constructor(private injector: Injector) {        AppInjector = this.injector;      }    }

Now, you can use the AppInjector to find any service in anywhere of your code.

import {AppInjector} from '../app.module';const myService = AppInjector.get(MyService);

Another approach would consist of defining a custom decorator (a CustomInjectable to set the metadata for dependency injection:

export function CustomComponent(annotation: any) {  return function (target: Function) {    // DI configuration    var parentTarget = Object.getPrototypeOf(target.prototype).constructor;    var parentAnnotations = Reflect.getMetadata('design:paramtypes', parentTarget);    Reflect.defineMetadata('design:paramtypes', parentAnnotations, target);    // Component annotations / metadata    var annotations = Reflect.getOwnMetadata('annotations', target);    annotations = annotations || [];    annotations.push(annotation);    Reflect.defineMetadata('annotations', annotations, target);  }}

It will leverage the metadata from the parent constructor instead of its own ones. You can use it on the child class:

@Injectable()export class SomeService {  constructor(protected http:Http) {  }}@Component()export class BaseComponent {  constructor(private service:SomeService) {  }}@CustomComponent({  (...)})export class TestComponent extends BaseComponent {  constructor() {    super(arguments);  }  test() {    console.log('http = '+this.http);  }}

See this question for more details:

• Angular2 use imported libs from base class