Question

我尝试通过angular2 observable获取webservice，但我有错误

错误TypeError：无法读取未定义的属性'get'

我在app.module.ts中导入了HttpModule。我有currencyService的提供者。接下来我创建了currency.ts（界面）接下来我使用了我的currency.service.ts：

import { Injectable } from '@angular/core';
import { Http, Response } from '@angular/http';
import { Observable } from 'rxjs/Observable';

import 'rxjs/add/operator/map';

import { ICurrency } from './currency';

@Injectable()
export class CurrencyService {

    currency:Array<ICurrency>;

    constructor(private _http: Http);

    getCurrency(): Observable<ICurrency[]>{

        return this._http
            .get('https://api.fixer.io/latest?base=PLN&symbols=EUR,USD,GBP,CZK,CHF,RUB')
            .map(res: Response => <ICurrency[]>res.json());
    };

}

最后，currency.component.ts：

import { Component, OnInit } from '@angular/core';
import { ICurrency } from './currency';

import { CurrencyService } from './currency.service';

@Component({
  selector: 'app-currency',
  templateUrl: './template.html',
  styles: []
})
export class CurrencyComponent implements OnInit {

    currency: array<ICurrency>;
    error: string;

    constructor(private _currencyService: CurrencyService) { }    

    ngOnInit(){
        this.getCurrency();
    }

    getCurrency(){
        this._currencyService
            .getCurrency()
            .subscribe(
                currency => this.currency = currency,
                err => this.error = <any>error
            )
    }
}

这是我第一次尝试使用observable，我在Angular2中很新。我基于一些tutoria，观看几个并阅读，但我甚至不知道哪里可能是错误。

Answer 1

首先请添加花括号并从构造函数中删除分号。

现在，使用HttpClient而不是Http（假设你在Angular 5上）

在您的appModule中

 import {HttpClientModule} from '@angular/common/http';

在您的货币服务中

从'@ angular / common / http'导入{HttpClient};

constructor(private _http: HttpClient){}

Angular2 get observable ERROR TypeError：无法读取未定义的属性'get'

1 个答案: