Question

我想以100为例，但返回5000行。以及如何搭配使用地图。

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class PathsService {
  path = 'https://jsonplaceholder.typicode.com/';
  pathUser = this.path + 'users';
  pathPost = this.path + 'posts';
  pathContent = this.path + 'photos';
  pathPostUserId = this.pathPost + '/?userId=';

  constructor() { }
}
import { Injectable } from '@angular/core';
import { GetPosts } from '../entities/getPosts';
import { GetUsers } from '../entities/getUsers';
import { HttpClient } from '@angular/common/http';
import { GetDeneme } from '../entities/getdeneme';
import { PathsService } from './paths.service';
import { Observable } from 'rxjs';
import { map, take } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class GetdataService {

  constructor(private http: HttpClient, private constsPath: PathsService) {
    console.log(this.constsPath.pathPost);
    console.log(this.constsPath.pathContent);
    console.log(this.constsPath.pathUser);
    console.log(this.constsPath.pathPostUserId);
  }


  getPosts(userid): Observable<GetPosts[]> {
    if (userid) {
      const link: string = this.constsPath.pathPostUserId + userid;
      debugger;

     return this.http.get<GetPosts[]>(link);

    } else {
      return this.http.get<GetPosts[]>(this.constsPath.pathPost);
    }
  }
  getUsers(): Observable<GetUsers[]> {
    return this.http.get<GetUsers[]>(this.constsPath.pathUser);

  }
  getContents(): Observable<GetDeneme[]> {
    return this.http.get<GetDeneme[]>(this.constsPath.pathContent);
  }

  getProducts(seoUrl: string): Observable<GetDeneme[]> {

    if (seoUrl) {
      return this.http.get<GetDeneme[]>(this.constsPath.path + '/photos/' + seoUrl);
    } else {
      return this.http.get<GetDeneme[]>(this.constsPath.path + '/photos');
    }

  }
}
I want to take some for example 100 but return 5000 rows. and how can use map with
  getPosts(): any {
    debugger;
    this.postService.getContents().pipe(take(100)).subscribe(res => {
      this.getden = res;
    });
  };

我添加了我的代码博客服务链接； https://jsonplaceholder.typicode.com/photos; 我看着https://www.learnrxjs.io/operators/filtering/take.html这个页面无法正常工作或无法执行代码。为什么不起作用？

Answer 1

使用map运算符和slice一起获取N个没有的行

 getUsers(): Observable<GetUsers[]> {
    return this.http.get<GetUsers[]>(this.constsPath.pathUser)
       .pipe(
           map(x => x.slice(0, 100)))

  }

Angular rxjs6我无法回复我想要的地图和地图

1 个答案: