方法"of"未定义 - Angular 5 HTTP服务教程

Question

我正在阅读Angular 5 http 教程.一切都运行良好,直到我坚持这个奇怪的结构我的离子项目抛出错误,"没有定义".

/**
* Handle Http operation that failed.
* Let the app continue.
* @param operation - name of the operation that failed
* @param result - optional value to return as the observable result
*/
private handleError<T> (operation = 'operation', result?: T) {
  return (error: any): Observable<T> => {

    // TODO: send the error to remote logging infrastructure
    console.error(error); // log to console instead

    // TODO: better job of transforming error for user consumption
    this.log(`${operation} failed: ${error.message}`);

    // Let the app keep running by returning an empty result.
    return of(result as T);
 };
}

我累了谷歌搜索这种"方法",但没有成功.这是教程中的错误吗？也许有些图书馆？

Answer 1

of是一个单独的功能.您需要of从rxjs包中导入功能.RxJS 5.5及更高版本将此技术与单独的函数一起使用.您需要导入的大多数功能,这使您可以拥有干净的代码,还可以使用捆绑工具进行一些优化.

import { of } from 'rxjs/observable/of'