我在使用Angular的组件时遇到了麻烦.我的应用程序只使用一个模块(app.module).我创建了一个名为’BooksComponent’的组件,其中包含一个用于html的选择器’app-books’.当我在app.component中使用它时,我收到此错误：
‘app-books’ is not a known element:
1. If ‘app-books’ is an Angular component,then verify that it is part of this module.
2. If ‘app-books’ is a Web Component then add ‘CUSTOM_ELEMENTS_SCHEMA’ to the ‘@NgModule.schemas’ of this component to suppress this message.
我的代码是这样的：
books.component.ts
import { Component,OnInit } from '@angular/core';
import { Book } from '../book';
import { BOOKS } from '../mock-books';
@Component({
selector: 'app-books',templateUrl: './books.component.html',styleUrls: ['./books.component.css']
})
export class BooksComponent implements OnInit {
books = BOOKS;
selectedBook : Book;
constructor() { }
ngOnInit() {
}
}
app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-root',template: `<h1>{{title}}</h1>
<app-books></app-books>`
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'BookShelf';
}
最后：
app.module.ts
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { BooksComponent } from './books/books.component';
import { BookDetailComponent } from './book-detail/book-detail.component';
@NgModule({
declarations: [
AppComponent,BooksComponent,BookDetailComponent,],imports: [
BrowserModule,FormsModule
],providers: [],bootstrap: [AppComponent]
})
export class AppModule { }
我已经在app模块中声明并导入BooksComponent,所以我无法理解我错过了什么！请帮忙！
解决方法
如果在运行测试时遇到错误,则可能意味着规范需要了解新组件BooksComponent.
要解决此问题,请将以下内容添加到app.component.spec.ts文件中.
import { BooksComponent } from './books/books.component';
在beforeEach()方法的声明中,添加如下所示的新组件：
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [
AppComponent,BooksComponent
],}).compileComponents();
}));
