我正在学习Angular2和Typescript。我正在研究angular.io上的英雄教程,但将其应用到我从ASP.Net转换而来的项目中。我遇到了一个我认为是因为我缺乏理解的问题,但据我所知,它与本教程的相关部分相匹配。可观察<{}>不可分配到类型可观察<SomeType[]>
import { Injectable } from '@angular/core';
import {RiskListSummary} from '../Models/RiskListSummary';
import { Observable } from 'rxjs/Rx';
import { Http, Response } from '@angular/http';
@Injectable()
export class RiskAssessmentListService {
constructor(private http : Http) {}
private serviceUrl = "http://myserviceurl/";
getRisks(): Observable<RiskListSummary[]> {
return this.http.get(this.serviceUrl)
.map(this.extractData())
.catch(this.handleError());
}
private extractData(res: Response) {
if (res.status < 200 || res.status >= 300) {
throw new Error('Bad response status: ' + res.status);
}
let body = res.json();
return body.data || { };
}
private handleError (error: any) {
let errMsg = error.message || 'Server error';
console.error(errMsg); // log to console instead
return Observable.throw(errMsg);
}
}
我收到以下错误就行了 “回归this.http.get(this.serviceUrl)”:
Error:(20, 16) TS2322: Type 'Observable<{}>' is not assignable to type 'Observable'. Type '{}' is not assignable to type 'RiskListSummary[]'. Property 'length' is missing in type '{}'.
如果它的确与众不同,我使用webstorm(最新版本),但我认为这个错误直接来自打字稿编译器。我在想也许我需要一个rxjs的打字文件,但教程不使用一个,而我发现的“打字搜索”中找不到的打了个差别
以下是我对软件包的依赖关系。 JSON:
"dependencies": {
"@angular/common": "2.0.0-rc.1",
"@angular/compiler": "2.0.0-rc.1",
"@angular/core": "2.0.0-rc.1",
"@angular/http": "2.0.0-rc.1",
"@angular/platform-browser": "2.0.0-rc.1",
"@angular/platform-browser-dynamic": "2.0.0-rc.1",
"@angular/router": "2.0.0-rc.1",
"@angular/router-deprecated": "2.0.0-rc.1",
"@angular/upgrade": "2.0.0-rc.1",
"systemjs": "0.19.27",
"es6-shim": "^0.35.0",
"reflect-metadata": "^0.1.3",
"rxjs": "5.0.0-beta.6",
"zone.js": "^0.6.12"
谢谢,这个技巧就是这样做的,我假设在原始示例中有.Net的扩展方法在工作(https: //angular.io/docs/ts/latest/guide/server-communication.html#)我想我需要开始一个新的项目,看看他们的例子是否仍然给出相同的错误 –