RXJS订阅编写

Question

经过教程后，我注意到“订阅”正在弃用。我尝试关注 https：//rxjs.dev/deprecations/subscribe-arguments-subscribe-arguments 如< typescript折旧警告，但无法更新到新方法。

我包括有关代码。任何帮助指出我出错的位置，以将弃用的方法移植到新方法的位置。

public books: Book[] | undefined;

  constructor(private bookService: BookService) {}

  ngOnInit() { this.getBooks(); }


  public getBooks(): void{
    // Reference: https://rxjs.dev/deprecations/subscribe-arguments

    // **deprecated:** This work, and I can see this.books has values
    // this.bookService.getBooks().subscribe(
    //   (response: Book[])=>{this.books=response},
    //   (error: HttpErrorResponse)=> {alert(error.message);}
    // );


    // **New approach**  This compiles but value is undefined.
    of([this.bookService.getBooks()]).subscribe({
        next: (value:any) => {
          this.books=value;
          console.info("Next: "+value.text); //console shows value is undefined
        },
        error: (value) => {
          alert(value.message);
        },
        complete: () => {
          console.info('complete');
        }
      }
    );

export interface Book{
  title: string;
  author: string;
}

Answer 1

我想此处的错误是您包装this.bookService.getBooks（）在数组中。如果您卸下方括号，则应工作。

另外，您无需在此处使用（）的。只需订阅正常即可。

this.bookService.getBooks().subscribe({
  next: (value) => {
    this.books=value;
    console.info("Next: "+value.text); //console shows value is undefined
  },
  error: (value) => {
    alert(value.message);
  },
  complete: () => {
    console.info('complete');
  }
});