类型'void'上不存在属性'subscribe'.Angular 2 asp.net核心

Question

当我尝试使用订阅时,我收到以下错误.我在.map中遇到了同样的问题,但我通过替换以下文件解决了这个问题:https://raw.githubusercontent.com/Microsoft/TypeScript/Fix8518/lib/typescriptServices.js

我已将Typescript更新为1.8.6并更新了visual studio 2015以更新3.

我不知道如何解决这个问题,或者如果我做错了什么,我也补充说

import 'rxjs/Rx'; 

到bootstrap和app.component类,仍然是同样的错误.

服务代码:

import { Injectable } from 'angular2/core';
import {Http, URLSearchParams} from "angular2/http";
import 'rxjs/add/operator/map';

@Injectable()
export class MediaItemService {

constructor(public http: Http) {
    this.http = http;
}

//functions
get() {
   // return this.mediaItems;
    this.http.get("/api/MediaItem").map(response => { response.json() });
}
}

使用服务的类:

import {Component, Inject} from 'angular2/core';
import 'rxjs/Rx'; 
import {MediaItemComponent} from './media-item.component';
import {CategoryListPipe} from './category-list.pipe';
import {MediaItemService} from './media-item.service';

@Component({
selector: 'media-item-list',
directives: [MediaItemComponent],
pipes: [CategoryListPipe],
providers: [MediaItemService],
templateUrl: 'app/media-item-list.component.html',
styleUrls: ['app/media-item-list.component.css']
})
export class MediaItemListComponent {


constructor(private mediaItemService: MediaItemService) {

        //.subscribe(mediaItems => {
        //    this.mediaItems = mediaItems;
        //});
}

ngOnInit() {
    this.mediaItems = this.mediaItemService.get().subscribe(mediaItems => {
            this.mediaItems = mediaItems;
        });
}

onMediaItemDeleted(mediaItem) {

    this.mediaItemService.delete(mediaItem);
}

mediaItems; 
}

package.json文件:

{
"version": "1.0.0",
"name": "TestFunWithAngi",
"private": true,
"dependencies": {
"angular2": "^2.0.0-beta.17",
"systemjs": "^0.19.31",
"es6-promise": "^3.2.1",
"es6-shim": "^0.35.1",
"reflect-metadata": "^0.1.3",
"rxjs": "^5.0.0-beta.9",
"tsd": "^0.6.5",
"zone.js": "^0.6.12"
},
"devDependencies": {
"typescript": "^1.8.10",
"typings": "^0.8.1",
"grunt": "1.0.1",
"grunt-contrib-copy": "1.0.0",
"grunt-contrib-uglify": "1.0.1",
"grunt-contrib-watch": "1.0.0",
"grunt-ts": "5.5.1"

}
}

Answer 1

你忘了回来了get().也不要在不返回内容的情况下封装lambda函数体.如果你这样做,就会发生隐含的回报response => response.json().否则你必须这样写:response => { return response.json(); }.

以下是您的方法的改进版本:

get() {
   // return this.mediaItems;
   return this.http.get("/api/MediaItem").map(response => response.json());
}

也只是省略this.http = http;你的构造函数.编写public或private在构造函数参数前面已经将它添加为类成员.