动手写一个angular版本的Message组件的方法(2)

//ComponentFactory的create方法
create(injector: Injector, projectableNodes?: any[][], rootSelectorOrNode?: string|any, ngModule?: NgModuleRef<any>): ComponentRef<C>

//使用Injector的create创建injector实例
static create(providers: StaticProvider[], parent?: Injector): Injector

import {
  ComponentFactoryResolver,
  ComponentFactory,
  ComponentRef,
  Type,
  Injector,
  Provider,
  ElementRef
} from '@angular/core';
export class ComponentLoader<T>{
  constructor(private _cfr: ComponentFactoryResolver,
    private _injector: Injector) {
  }
  private _componentFactory: ComponentFactory<T>
  attch(componentType: Type<T>): ComponentLoader<T> {
    this._componentFactory = this._cfr.resolveComponentFactory<T>(componentType);
    return this;
  }
  private _parent: Element
  to(parent: string | ElementRef): ComponentLoader<T> {
    if (parent instanceof ElementRef) {
      this._parent = parent.nativeElement;
    } else {
      this._parent = document.querySelector(parent);
    }

    return this;
  }
  private _providers: Provider[] = [];
  provider(provider: Provider) {
    this._providers.push(provider);
  }
  create(opts: {}): ComponentRef<T> {
    const injector = Injector.create(this._providers as any[], this._injector);
    const componentRef = this._componentFactory.create(injector);
    Object.assign(componentRef.instance, opts);
    if (this._parent) {
      this._parent.appendChild(componentRef.location.nativeElement);
    }
    componentRef.changeDetectorRef.markForCheck();
    componentRef.changeDetectorRef.detectChanges();
    return componentRef;
  }
  remove(ref:ComponentRef<T>){
    if(this._parent){
      this._parent.removeChild(ref.location.nativeElement)
    }
    ref=null;
  }
}

import {
  ComponentFactoryResolver,
  Injector,
  Injectable,
  ElementRef
} from '@angular/core';
import { ComponentLoader } from './component-loader.class';

@Injectable()
export class ComponentLoaderFactory {
  constructor(private _injector: Injector,
    private _cfr: ComponentFactoryResolver) {

  }

  create<T>(): ComponentLoader<T> {
    return new ComponentLoader(this._cfr, this._injector);
  }
}