Question

尝试修复旧代码，但出现错误，无法正确命名“书”。我对此很陌生，因此可以提供任何帮助。是否应该以某种方式涉及课堂教学？ src / app / app.component.ts（31,27）中发生错误：错误TS2304：找不到名称“书”。

   import { Component } from '@angular/core';
import { AngularFireDatabase, AngularFireList } from '@angular/fire/database';

@Component({
  selector: 'app-root',
  template: `
      <ul>
          <li *ngFor="let book of books | async">
              <pre>{{ book | json }}</pre>
          </li>
      </ul>
      <button (click)="addBook()">Add a book!</button>
      <button (click)="filterBooks()">Filter books</button>
  `
})


export class AppComponent {

  public books: AngularFireList<any[]>;

  private bookCounter = 0;

  private filter = '';

  constructor(public title, private af: AngularFireDatabase) {
      this.books = af.list('/books');
  }

  public addBook(): void {
      const newBook = new book(`My book #${this.bookCounter++}`);
      this.books.push(newBook);
  }

  public filterBooks(): void {
      this.books = this.af.list('/books', ref =>
      ref.orderByChild('title').equalTo('My book #1'));

  }
}

Answer 1

好像您正在尝试实例化一本书类：

const newBook = new book(`My book #${this.bookCounter++}`);

但是您尚未导入book类，因此只需导入它，它应该可以解决您的错误。

遇到错误，找不到名称“ book” Angular 7

1 个答案: