angular – 具有多个参数和注入项的TypeScript构造函数

它看起来像这样.

image-item.ts定义了一个简单的类：

import { DomSanitizer } from '@angular/platform-browser';

export class ImageItem {
    constructor(public Id: number,private _sanitizer: DomSanitizer) {
    }
}

该工厂是一个注入服务,注入DomSanitizer并具有一个能够创建ImageItem实例的方法.

import { Injectable } from '@angular/core';
import { DomSanitizer } from '@angular/platform-browser';
import { ImageItem } from './image-item';

@Injectable()
export class ImageItemFactoryService {

  constructor(private domSanitizer: DomSanitizer) { }

  public createImageItem(id: number,description: string) {
    return new ImageItem(id,'',description,this.domSanitizer);
  }
}

app.component.ts将工厂作为提供程序导入,并使用它来创建ImageItem的实例.

import { Component } from '@angular/core';
import { ImageItem } from './image-item';
import { ImageItemFactoryService } from './image-item-factory.service';
@Component({
  selector: 'app-root',templateUrl: './app.component.html',styleUrls: ['./app.component.css'],providers: [ImageItemFactoryService]
})
export class AppComponent {
  private item: ImageItem = null;
  constructor(public imageItemFactory: ImageItemFactoryService) {
    this.item = imageItemFactory.createImageItem(1,'something');
  }
}

在angularjs(1)中,可以使用注射器来创建实例,并且可以同时在注射期间给出一些局部值.

在角度(2)中,Injector服务不再提供该功能.