Angular 2 HTTP“无法解析‘AppService’的所有参数" [英] Angular 2 HTTP "Cannot resolve all parameters for 'AppService'"

问题描述

我尝试将 http 提供程序导入到服务中，但出现以下错误:

I tried to import the http provider into a service, but I'm getting the following error:

无法解析AppService"(?) 的所有参数.确保所有参数都使用 Inject 修饰或具有有效的类型注释，并且AppService"使用 Injectable 修饰.

Cannot resolve all parameters for 'AppService'(?). Make sure that all the parameters are decorated with Inject or have valid type annotations and that 'AppService' is decorated with Injectable.

以下是一些代码片段:

<script src="~/es6-shim/es6-shim.min.js"></script>
<script src="~/systemjs/dist/system-polyfills.js"></script>

<script src="~/angular2/bundles/angular2-polyfills.js"></script>
<script src="~/systemjs/dist/system.src.js"></script>
<script src="~/rxjs/bundles/Rx.js"></script>
<script src="~/angular2/bundles/angular2.dev.js"></script>
<script src="~/angular2/bundles/http.dev.js"></script>

<!-- 2. Configure SystemJS -->
<script>
    System.config({
        map: { 'rxjs': 'RCO/rxjs' },
        packages: {
            RCO: {
                format: 'register',
                defaultExtension: 'js'
            },
            'rxjs': {defaultExtension: 'js'}
        }
    });
  System.import('RCO/Areas/ViewOrganization/AngularTemplates/boot')
      .then(null, console.error.bind(console));

boot.ts

import {bootstrap} from 'angular2/platform/browser'
import {HTTP_PROVIDERS} from 'angular2/http'
import 'rxjs/add/operator/map'
import {AppComponent} from  'RCO/Areas/ViewOrganization/AngularTemplates/app.component'
import {AppService} from 'RCO/Areas/ViewOrganization/AngularTemplates/app.service'

bootstrap(AppComponent, [HTTP_PROVIDERS, AppService]);

app.service.ts

app.service.ts

import {Injectable} from 'angular2/core';
import {Http, Response} from 'angular2/http';
import {Observable} from 'rxjs/Rx';

@Injectable()
export class AppService {

    constructor(private http: Http) { }

    // Uses http.get() to load a single JSON file
    getTableData() {
        return this.http.get('...').map((res: Response) => res.json());
    }

}

我正在尝试调用服务器上的控制器以最终将 JSON 文件加载到数据表中.非常简单的东西，但我加载 Http 模块的方式似乎是错误的.任何帮助将不胜感激.

I'm trying to call a controller on the server to eventually load a JSON file into a data table. Pretty straightforward stuff, but the way I'm loading the Http modules seems to be wrong. Any help will be much appreciated.

推荐答案

似乎您没有使用 typescript 编译器将文件转换为 js，在这种情况下，您需要在组件构造函数中注入任何依赖项时使用 @Inject.

Seems like you are not using typescript compiler for transpiling files to js, In that case you need to have use @Inject while injecting any dependency inside a component constructor.

import {Injectable, Inject} from 'angular2/core';
import {Http, Response} from 'angular2/http';
import {Observable} from 'rxjs/Rx';

@Injectable()
export class AppService {
    constructor(@Inject(Http) private http: Http) { }
    // Uses http.get() to load a single JSON file
    getTableData() {
        return this.http.get('...').map((res: Response) => res.json());
    }
}

这篇关于Angular 2 HTTP“无法解析‘AppService’的所有参数"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！