订阅不是一个功能 - ionic 4

Question

我正在尝试在我的 ionic 4 项目中使用 api 获取一些数据。我遵循了这个指南：

https://ionicacademy.com/http-calls-ionic/

这是我的 list.page.ts :

import { Component, OnInit } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-list',
  templateUrl: 'list.page.html',
  styleUrls: ['list.page.scss']
})
export class ListPage implements OnInit {

  private selectedItem: any;
  private icons = [
    'flask',
    'wifi',
    'beer',
    'football',
    'basketball',
    'paper-plane',
    'american-football',
    'boat',
    'bluetooth',
    'build'
  ];
  public items: Array<{ title: string; note: string; icon: string }> = [];
  items: Observable<any>;
  constructor(public httpClient: HttpClient){
    this.item = this.httpClient.get('http://www.fostania.com/api/items/');
this.items.subscribe(data => {
  console.log('my data: ', data);
})
}



  ngOnInit() {
  }
  // add back when alpha.4 is out
  // navigate(item) {
  //   this.router.navigate(['/list', JSON.stringify(item)]);
  // }
}

当我尝试访问此页面时出现错误：

core.js:15723 ERROR Error: Uncaught (in promise): TypeError: this.items.subscribe is not a function

Answer 1

您已将 http get observable 分配给 this.item 字段。在下一行中，您应该使用 this.item 而不是 this.items 来订阅它，并且可能将结果保存在订阅内部，如 this.items = data 以便稍后处理。

订阅不是一个功能 - ionic 4

subscribe is not a function - ionic 4

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