angular – Subscription’不能分配给类型
发布时间:2020-12-17 17:29:16 所属栏目:安全 来源:网络整理
导读:我在获取服务以在页面上显示结果时遇到问题.错误是订阅方法返回订阅类型,我不知道试图将它带到产品数组.产品位于json文件中. 建立: 我正在尝试通过阅读教程来学习Angular 2.教程已过时,我正在使用最新版本的angular(ng -v = @ angular / cli:1.4.2).我使用
我在获取服务以在页面上显示结果时遇到问题.错误是订阅方法返回订阅类型,我不知道试图将它带到产品数组.产品位于json文件中.
建立: 产品list.component.ts export class ProductListComponent implements OnInit { pageTitle = 'Product List'; imageWidth = 50; imageMargin = 2; showImage = false; listFilter = ''; products: IProductList[]; subscription: Subscription; errorMessage = ''; constructor(private _productListService: ProductListService) { } ngOnInit() { **// ERROR - 'Subscription' is not assignable to type 'IProductList[]'** this.products = this._productListService.getProducts() // ******** ERROR ****** .subscribe( products => this.products = products,error => this.errorMessage = <any>error); } 产品list.service.ts import { Injectable } from '@angular/core'; import { Http,Response } from '@angular/http'; import { Observable } from 'rxjs/Observable'; import { IProductList } from './product-list'; @Injectable() export class ProductListService { private _productListUrl = 'api/product-list/product-list.json'; constructor(private _http: Http) { } getProducts(): Observable<IProductList[]> { return this._http.get(this._productListUrl) .map((response: Response) => <IProductList[]>response.json()) .do(data => console.log('All: ' + JSON.stringify(data))) .catch(this.handleError); } private handleError(error: Response) { console.error(error); return Observable.throw(error.json().error || 'Server Error'); } } 产品list.component.html <tr *ngFor='let product of products | async | productFilter: listFilter' > <td> <img *ngIf='showImage' [src]='product.imageUrl' [title]='product.productName' [style.width.px]='imageWidth' [style.marging.px]='imageMargin'> </td> <td>{{product.productName}}</td> <td>{{product.productCode | lowercase }}</td> <td>{{product.releaseDate}}</td> <td>{{product.price | currency:'USD':true:'1.2-2' }}</td> <td><app-ai-star [rating] = 'product.starRating' (ratingClicked)='onRatingClicked($event)'></app-ai-star></td> </tr> 解决方法
问题是你想让你的订阅= getProducts()调用.
ngOnInit() { this.subscription = this._productListService.getProducts() // subscription created here .subscribe( products => this.products = products,// value applied to products here error => this.errorMessage = <any>error); } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |