通用类型"Observable T"需要1个类型的参数 [英] Generic type 'Observable<T>' requires 1 type argument

问题描述

下面的Angular 2(TypeScript)代码给了我3以下的错误，如何解决它们.请提出建议.

Below Angular 2 (TypeScript) code gave me below 3 error, how to resolve them. please suggest.

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { NgModule, Component } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule, Http } from '@angular/http';
import 'rxjs/add/operator/map';
import { Observable } from "rxjs/Observable";

@Component({
    selector: 'http-client',
    template: `<h1>All Products</h1>
  <ul>
    <li *ngFor="let product of products">
       {{product.title}}
    </li>
  </ul>
  `})
class AppComponent {

    products: Array<string> = [];

    theDataSource: Observable;

    constructor(private http: Http) {

        this.theDataSource = this.http.get('api/products/')
            .map(res => res.json());
    }

    ngOnInit() {
        // Get the data from the server
        this.theDataSource.subscribe(
            data => {
                if (Array.isArray(data)) {
                    this.products = data;
                } else {
                    this.products.push(data);
                }
            },
            err =>
                console.log("Can't get products. Error code: %s, URL: %s ", err.status, err.url),
            () => console.log('Product(s) are retrieved')
        );
    }
}

@NgModule({
    imports: [BrowserModule,
        HttpModule],
    declarations: [AppComponent],
    bootstrap: [AppComponent]
})
class AppModule { }

platformBrowserDynamic().bootstrapModule(AppModule);

错误是

1. TS2314通用类型可观察"需要1个类型参数.
2. TS7006参数'data'隐式具有'any'类型.
3. TS7006参数'err'隐式具有'any'类型.

推荐答案

theDataSource: Observable<any>;

其中any可以(或者应该尽可能)是更具体的类型，与应该发出的值的类型匹配.

where any can (or should be if possible) be a more concrete type that matches the type of the values it is supposed to emit.

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