使用 Angular 2 和 Typescript 从 url (web api) 获取 Json 对象

Question

`嗨， 我需要一些帮助才能从 Visual Studio 2015 .net Core、Angular 2 和 Typescript 上的 Web API 获取 JSON 数据。 /wwwroot/libs 中的 Angular2 文件夹。

我正在使用 Angular 2 的 http.get()。 get() 函数的结果显示一个未定义的值...为什么？

这是我的文件：

Folders

[API][2]

CustomersController.cs => 通过http://localhost:45149/api/customers/ 访问 OK => [{...},{...},{...}]

public class CustomersController : Controller
{
    // GET: api/customers 
    [HttpGet]
    public IList<Customer> Get()
    {
        var objects = new List<Customer>
        {
            new Customer { Id = 1, Log = "user01", Name = "user1" },
            new Customer { Id = 2, Log = "user02", Name = "user2" },
            new Customer { Id = 3, Log = "user03", Name = "user3" }
        };
        return objects;
    }
}

customer.ts

export class Customer {
constructor(
    public Id: number,
    public Log: string,
    public Name: string
    ){}
}

customer.service.ts

import { Injectable } from "@angular/core";
import { Http } from "@angular/http";
import { Observable } from "rxjs/Observable";
import { Customer } from "./customer";
import "rxjs/Rx"

@Injectable()
export class CustomerService {
private baseUrl = "http://localhost:45149/api/customers/";  // web api URL
constructor(private http: Http) { }

getCustomers() {
    return this.http.get(this.baseUrl)
        .map(res => <Customer[]> res.json())
        .catch(error => {
            console.log(error);
            return Observable.throw(error);
        });
}}

customer.component.ts

import { Component, OnInit } from '@angular/core';
import { HTTP_PROVIDERS } from '@angular/http';
import { Customer } from './customer';
import { CustomerService } from './customer.service'

@Component({
selector: 'app-api',
template: ` 
<ul class="">
<li *ngFor="let customer of customers">
<span class=""> 
{{customer.Id}} </span> {{customer.Name}}
</li>
</ul>`,
    providers: [
            HTTP_PROVIDERS,
            CustomerService
    ] }) 

    export class CustomerComponent implements OnInit{
    api: string;
    public customers: Customer[];

    constructor(private customerService: CustomerService) {
    this.api = "API Customers"; 
}

ngOnInit() {
    this.customerService.getCustomers()
        .subscribe(
        customers =>
        {
            console.log(this.customers);
            this.customers = customers;
        },
        error => alert("error"));
}}

app.module.ts

// 
*** Imports ***
//

@NgModule({
imports: [BrowserModule, routing], //other modules the app depends on
providers: [CustomerService],
declarations: [AppComponent,
HomeComponent,UploadComponent,CustomerComponent],
bootstrap: [AppComponent] // root component to bootstarp
})

export class AppModule { }

app.component.ts

import { Component } from '@angular/core';

@Component({
selector: 'app-root',
templateUrl: './app/app.component.html' // => SPA
})

export class AppComponent {
title = "App-root"
}

谢谢。

Answer 1

当您尝试绑定到具有大写名称的属性时，您的服务器似乎设置为使用骆驼大小写序列化响应。

如果您希望将序列化程序设置更改为使用其他格式，请查看以下文章：Web API serialize properties starting from lowercase letter。

否则你应该可以绑定到角边的小写名称