TypeError：无法使用Angular v6读取未定义的属性“map”

Question

由于某些原因，JSON的响应映射不正确，这里是我的HTML。配置文件-search.component.html

<h3>Enter Username</h3>
<input (keyup)="search($event.target.value)" id="name" placeholder="Search"/>
<ul>
  <li *ngFor="let package of packages$ | async">
    <b>{{package.name}} v.{{package.repos}}</b> -
    <i>{{package.stars}}</i>`enter code here`
  </li>
</ul>

下面是html从中提取的组件。配置文件-search.component.ts

import { Component, OnInit } from '@angular/core';

import { Observable, Subject } from 'rxjs';
import { debounceTime, distinctUntilChanged, switchMap } from 'rxjs/operators';

import { NpmPackageInfo, PackageSearchService } from './profile-search.service';

@Component({
  selector: 'app-package-search',
  templateUrl: './profile-search.component.html',
  providers: [ PackageSearchService ]
})
export class PackageSearchComponent implements OnInit {
  withRefresh = false;
  packages$: Observable<NpmPackageInfo[]>;
  private searchText$ = new Subject<string>();

  search(packageName: string) {
    this.searchText$.next(packageName);
  }

  ngOnInit() {
    this.packages$ = this.searchText$.pipe(
      debounceTime(500),
      distinctUntilChanged(),
      switchMap(packageName =>
        this.searchService.search(packageName, this.withRefresh))
    );
  }

  constructor(private searchService: PackageSearchService) { }


  toggleRefresh() { this.withRefresh = ! this.withRefresh; }

}

import { Injectable, Input } from '@angular/core';
import { HttpClient, HttpHeaders, HttpParams } from '@angular/common/http';

import { Observable, of } from 'rxjs';
import { catchError, map } from 'rxjs/operators';

import { HttpErrorHandler, HandleError } from '../http-error-handler.service';

export interface NpmPackageInfo {
  name: string;
}

export const searchUrl = 'https://api.github.com/users';

const httpOptions = {
  headers: new HttpHeaders({
    'x-refresh':  'true'
  })
};

function createHttpOptions(packageName: string, refresh = false) {
    // npm package name search api
    // e.g., http://npmsearch.com/query?q=dom'
    const params = new HttpParams({ fromObject: { q: packageName } });
    const headerMap = refresh ? {'x-refresh': 'true'} : {};
    const headers = new HttpHeaders(headerMap) ;
    return { headers, params };
}

@Injectable()
export class PackageSearchService {
  private handleError: HandleError;

  constructor(
    private http: HttpClient,
    httpErrorHandler: HttpErrorHandler) {
    this.handleError = httpErrorHandler.createHandleError('HeroesService');
  }

  search (packageName: string, refresh = false): Observable<NpmPackageInfo[]> {
    // clear if no pkg name
    if (!packageName.trim()) { return of([]); }

    // const options = createHttpOptions(packageName, refresh);

    // TODO: Add error handling
    return this.http.get(`${searchUrl}/${packageName}`).pipe(
      map((data: any) => {
        return data.results.map(entry => ({
            name: entry.any[0],
          } as NpmPackageInfo )
        )
      }),
      catchError(this.handleError('search', []))
    );
  }
}

return this.http.get(`${searchUrl}/${packageName}`).pipe(
    map((data: any) => {
        return data.results.map(entry => ({
            name: entry.any[0],
          } as NpmPackageInfo )
        )

http-error-handler.service.ts：33类型错误：无法读取MapSubscriber.Project（profile-search.service.ts：49）在MapSubscriber.push../node_modules/rxjs/_esm5/internal/operators/map.js.mapSubscriber._next(map.js:75)在MapSubscriber.push./node_modules/rxjs/_esm5/internal/subscriber.js.subscriber.next(subscriber.js:93)在MapSubscriber.push./node_modules/rxjs/_esm5/internal/operators/map.js.mapsubscriber._next node_modules/rxjs/_esm5/internal/subscriber.js.subscriber.next(Subscriber.js:93)位于filtersubscriber.push./node_modules/rxjs/_esm5/internal/operators/filter.js.filtersubscriber._next(Filter.js:85)位于filtersubscriber.push./node_modules/rxjs/_esm5/internal/subscriber.js.subscriber.next(Subscriber.js:93)位于mergeMapsubscriber.push./node_modules/rxjs/_esm5/internal/operators/mergeMapsubscriber.notifyNext s:136)在innersubscriber.push../node_modules/rxjs/_esm5/internal/innersubscriber.js.innersubscriber._next(innersubscriber.js:20)位于innersubscriber.push../node_modules/rxjs/_esm5/internal/subscriber.js.subscriber.next(subscriber.js:93)

Answer 1

data.results中的results可能是未定义的，请检查data对象是否与您期望的架构匹配。