Subject.next() 中的值更改时未调用 Observable

Question

我正在尝试构建一个自动完成功能，并且我正在使用 Observable 和 Subject。但是只要 Subject 对象的值发生变化，就不会调用服务方法。下面是我定义主题的组件代码。

detailsPersist.component.ts

import { Component, OnInit } from "@angular/core";
import { Subject } from 'rxjs/Subject';
import { DataService } from './data.service';

export class DetailsPersistComponent implements OnInit{
products;
term = new Subject();
constructor(private _dataService: DataService){

  }
ngOnInit(){
        this._dataService.getSwiftProducts(this.term)
          .subscribe(products => this.products = products)
  }

  search($event) {
        let q = $event.target.value
        console.log(q)
        this.term.next(q)
    }
}

下面是我的数据服务的代码

data.service.ts

import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions, URLSearchParams } from '@angular/http';
import 'rxjs/add/operator/map';
import {Observable} from 'rxjs';


@Injectable()
export class DataService{
 getSwiftProducts(term): Observable<any>{
    return this._http.get("/api/getSwiftProduct/:"+term)
      .map(result => this.result = result.json().data)
  }
}

Answer 1

您可能想做这样的事情：

ngOnInit() {
  this.subscription = this.term
    .switchMap(term => this._dataService.getSwiftProducts(term))
    .subscribe(products => this.products = products)
}

ngOnDestroy() {
  this.subscription.unsubscribe();
}

Subject.next() 中的值更改时未调用 Observable

Observable not being called on value change in Subject.next()

rxjs

rxjs5

angular