如何从 asObservable() 获取数据

Question

这是我的服务代码，让服务名称为setGetContext

_params: Subject<any> = new Subject<any>();

getParameters(): Observable<SearchContext> {
    return this._params.asObservable();
}

setParameters(search: SearchContext) {
    this._params.next("Test");
}

在另一个组件中，我试图获取参数的值。

this.setGetContext.getParameters().subscribe((data) => {
    console.log(data);
})

这里我没有获取数据，甚至没有触发代码。

Answer 1

服务：

public _params: Subject<any> = new Subject<any>();
setParameters(search: SearchContext) {
  this._params.next({action:'test'});
}

组件：

import { Component, OnInit, OnDestroy } from '@angular/core';
import { Subscription } from 'rxjs';
import { Your service } from 'service_route'

export class YourComponent implements OnInit {
    public subscription: Subscription;

    constructor(private _serv: YourService) {}

    ngOnInit() {
       this.handleSubscriptions();
    }
    public handleSubscriptions() {
      this.subscription = this._serv._params.subscribe(
        action => {
            console.log(action);
        }
      )
    }
}

现在您可以调用您的服务函数，每次调用它时您的组件都会 console.log 'test'

Answer 2

你可以这样做：

您的服务：

import { Observable } from "rxjs/Observable";
import { BehaviorSubject } from 'rxjs/BehaviorSubject';
import { distinctUntilChanged, map } from 'rxjs/operators';

private _paramSubject = new BehaviorSubject<any>({} as any);
public _params = this._paramSubject.asObservable().pipe(distinctUntilChanged());

setParameters(search: SearchContext) {
    this._paramSubject.next("Test");
}

组件中：

setParameters(<YOUR OBJECT>)
service._params.subscribe(data => {console.log(data)});

如何从 asObservable() 获取数据

How to get data from asObservable()

angular

observable

angular2-observables

query-parameters