'OperatorFunction<Response, {}>' 类型上不存在属性 'subscribe'

Question

我知道这已经被问过很多次了，但是，我无法弄清楚如何使用以下帖子更改我自己的代码。

Property 'subscribe' does not exist on type 'OperatorFunction<Response, Recipe[]>'

Property 'subscribe' does not exist on type 'OperatorFunction<Product[], ParamMap>'

Property 'subscribe' does not exist on type 'OperatorFunction<unknown, any>'

---

rest-api.service.ts

specificObjectRequest(ids: string[]): Observable<any> {
  var idString = ids.join(); 
  const url = `${ApiServerUrl}/media_objects?ID=${idString}`;
  console.log("requesting from url: " + url);
  this.http.get(url, {}, {})
    .then(res => this.extractData = res.data)
    .catch(this.handleError);
  return;
}

tagRequest(topic: string){
    var url = `${ApiServerUrl}/tags?topic=${topic}`;
    url = encodeURI(url);
    console.log("requesting from url: " + url);
    this.http.get(url, {}, {})
      .then(res => this.extractData = res.data)
      .catch(this.handleError);
    return map(this.extractData);
  }

我使用官方文档https://ionicframework.com/docs/native/http 和本教程创建了这个请求

filter.page.ts

async requestMapTags(topic: string){
    await this.api.tagRequest(topic).subscribe(res => {  //Property 'subscribe' does not exist on type 'OperatorFunction<Response, {}>'
      console.log(res);
      this.tagsRequestAnswer = res; 
    }, err => {
      console.log(err);
    });
}

错误信息：

[ng] ERROR in src/app/filter/filter.page.ts(89,35): error TS2339: Property 'subscribe' does not exist on type 'OperatorFunction<Response, {}>'.

从我的阅读来看，这是 Promises 和 rxjs 之间的冲突。

问题： 我需要更改什么才能使其正常工作？有没有办法在我的代码中添加所需的“管道”函数以使其工作？

Answer 1

在这里使用promises似乎没有必要，你可以更轻松地做到这一点

import { of } from 'rxjs';

tagRequest(topic: string){
    var url = `${ApiServerUrl}/tags?topic=${topic}`;
    url = encodeURI(url);
    return of(this.http.get(url, {}, {})).pipe(map(res => res.data));
  }

requestMapTags(topic: string){
    this.api.tagRequest(topic).subscribe(res => { 
      console.log(res);
      this.tagsRequestAnswer = res; 
    }, err => {
      console.log(err);
    });
}

Answer 2

您的tagRequest() 需要有一个返回值作为Observable 而不是OperatorFunction<Response, {}>；

所以试试这样的：

import { from } from 'rxjs';

tagRequest(topic: string){
    var url = `${ApiServerUrl}/tags?topic=${topic}`;
    url = encodeURI(url);
    console.log("requesting from url: " + url);
    return from(this.http.get(url, {}, {}));
  }