Angular 4 - 使用HttpModule我得到錯誤「沒有ConnectionBackend的提供者！」

Question

我是新來Angular4（和打字稿）和我已經收到此錯誤：

我app.module.ts是設置這樣的：

import { NgModule }  from '@angular/core'; 
import { BrowserModule } from '@angular/platform-browser'; 
import { FormsModule } from '@angular/forms'; 
import { HttpModule } from '@angular/http'; 

import { AppComponent } from './app.component'; 
import { CustomerListComponent } from './Customer-List/customer-list.component'; 
import { CustomerDetailsComponent } from './Customer-Details/customer-details.component'; 
import { DataService } from './services/data.service'; 


@NgModule({ 
    imports:  [ BrowserModule, FormsModule, HttpModule ], 
    declarations: [ AppComponent, CustomerListComponent, CustomerDetailsComponent ], 
    providers: [ DataService ], 
    bootstrap: [ AppComponent ] 
}) 
export class AppModule { } 

我有一個服務（稱爲DataService的）使用HTTP模塊下面的代碼：

import { Injectable } from '@angular/core'; 
    import { Http, Response, RequestOptions, Headers } from '@angular/http'; 
    import { CreateTestCustomers } from '../data/test-data'; 
    import { Customer } from '../Models/customerModel'; 

    @Injectable() 
    export class DataService { 

     private customersUrl = 'http://localhost:52740/api/Customers/'; 

     constructor(
      private http : Http 
     ) { } 

     getCustomersP() : Promise<Customer[]>{ 
       const customers = CreateTestCustomers(); 

       return this.http.get(this.customersUrl) 
        .toPromise() 
        .then(response => { 
         const custs = response.json().data as Customer[]; 
         return custs; 
        }, error => { 
         return Promise.reject('Something bad happened, please check the console'); 
        },); 
      } 
    } 

當我嘗試編譯我的應用程序，我得到這個奇怪的錯誤：

Unhandled Promise rejection: No provider for ConnectionBackend! ; Zone: <root> ; Task: Promise.then ; Value: Error: No provider for ConnectionBackend! Error: No provider for ConnectionBackend! 
    at ReflectiveInjector_.prototype._throwOrNull (eval code:2681:13) 
    at ReflectiveInjector_.prototype._getByKeyDefault (eval code:2720:13) 
    at ReflectiveInjector_.prototype._getByKey (eval code:2652:13) 
    at ReflectiveInjector_.prototype.get (eval code:2521:9) 
    at resolveNgModuleDep (eval code:9513:5) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13) 
    at resolveNgModuleDep (eval code:9508:13) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13) 
zone.js (661,17) 
    "Unhandled Promise rejection:" 
    "No provider for ConnectionBackend!" 
    "; Zone:" 
    "<root>" 
    "; Task:" 
    "Promise.then" 
    "; Value:" 
    { 
     [functions]: , 
     __proto__: { }, 
     __zone_symbol__currentTask: { }, 
     description: "No provider for ConnectionBackend!", 
     injectors: [ ], 
     keys: [ ], 
     message: "No provider for ConnectionBackend!", 
     name: "Error", 
     ngDebugContext: { }, 
     ngOriginalError: undefined, 
     stack: "Error: No provider for ConnectionBackend! 
    at ReflectiveInjector_.prototype._throwOrNull (eval code:2681:13) 
    at ReflectiveInjector_.prototype._getByKeyDefault (eval code:2720:13) 
    at ReflectiveInjector_.prototype._getByKey (eval code:2652:13) 
    at ReflectiveInjector_.prototype.get (eval code:2521:9) 
    at resolveNgModuleDep (eval code:9513:5) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13) 
    at resolveNgModuleDep (eval code:9508:13) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13)" 
    } 
    "Error: No provider for ConnectionBackend! 
    at ReflectiveInjector_.prototype._throwOrNull (eval code:2681:13) 
    at ReflectiveInjector_.prototype._getByKeyDefault (eval code:2720:13) 
    at ReflectiveInjector_.prototype._getByKey (eval code:2652:13) 
    at ReflectiveInjector_.prototype.get (eval code:2521:9) 
    at resolveNgModuleDep (eval code:9513:5) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13) 
    at resolveNgModuleDep (eval code:9508:13) 
    at _createClass (eval code:9555:13) 
    at _createProviderInstance$1 (eval code:9524:13)" 

有沒有人遇到過這個？一切都在網上似乎是指角2，並沒有修復它似乎幫助角4

我已經看到了這篇文章，但它沒有答案 - 我的問題類似於：提前angular 4 Error: Uncaught (in promise): Error: No provider for ConnectionBackend! while injecting Jsonp

謝謝！

Answer 1

不僅僅是答案，而是解決方法。我搭建了一個新項目，並逐個添加我的組件以解決此問題。不知道原始項目發生了什麼。