c# – Angular 4 – 如何从ASP.Net web api获取数据

然后我在项目中添加了一个新的ASP.Net Core 2.0 API控制器,它使用Entity Framework连接到数据库,并使其运行200 HTTP GET结果.

控制器代码：

#region TodoController
namespace TodoAngularUI.Controllers
{
    [Route("api/[controller]")]
    public class TodoController : Controller
    {
        private readonly SchoolContext _context;
        #endregion

        public TodoController(SchoolContext DbContext)
        {
            _context = DbContext;

            if (_context.Todo.Count() == 0)
            {
                _context.Todo.Add(new Todo { TaskName = "Item1" });
                _context.SaveChanges();
            }
        }

        #region snippet_GetAll
        [HttpGet]
        public IEnumerable<Todo> GetAll()
        {
            return _context.Todo.ToList();
        }

        [HttpGet("{id}",Name = "GetTodo")]
        public IActionResult GetById(long id)
        {
            var item = _context.Todo.FirstOrDefault(t => t.Id == id);
            if (item == null)
            {
                return NotFound();
            }
            return new ObjectResult(item);
        }
        #endregion

现在,我想使用Angular显示生成的ASP.Net Core控制器数据,因此我创建了一个名为“todo”的TypeScript组件,如下所示：

import { Component,Inject } from '@angular/core';
import { Http } from '@angular/http';

@Component({
    selector: 'todo',templateUrl: './todo.component.html'
})
export class TodoComponent {
    public Todo: task[];

    constructor(http: Http,@Inject('BASE_URL') baseUrl: string) {
        http.get(baseUrl + '/api/todo').subscribe(result => {
            this.Todo = result.json() as task[];
        },error => console.error(error));
    }
}

interface task {
    Id: number;
    TaskName: string;
    IsComplete: boolean;
}

并创建其HTML组件如下：

<h1>Todo tasks</h1>

<p>This component demonstrates fetching Todo tasks from the server.</p>

<p *ngIf="!todo"><em>Loading...</em></p>

<table class='table' *ngIf="Todo">
    <thead>
        <tr>
            <th>Id</th>
            <th>Task Name</th>
            <th>Is complete</th>
        </tr>
    </thead>
    <tbody>
        <tr *ngFor="let Task of todo">
            <td>{{ Task.Id }}</td>
            <td>{{ Task.TaskName }}</td>
            <td>{{ Task.Iscomplete }}</td>
        </tr>
    </tbody>
</table>

然后去Nav侧栏菜单中添加其路由,这里是TypeScript代码：

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

@Component({
    selector: 'nav-menu',templateUrl: './navmenu.component.html',styleUrls: ['./navmenu.component.css']
})
export class NavMenuComponent {
}

这是Navbar HTML代码：

<div class='main-nav'>
<div class='navbar navbar-inverse'>
    <div class='navbar-header'>
        <button type='button' class='navbar-toggle' data-toggle='collapse' data-target='.navbar-collapse'>
            <span class='sr-only'>Toggle navigation</span>
            <span class='icon-bar'></span>
            <span class='icon-bar'></span>
            <span class='icon-bar'></span>
            <span class='icon-bar'></span>
        </button>
        <a class='navbar-brand' [routerLink]="['/home']">TodoAngularUI</a>
    </div>
    <div class='clearfix'></div>
    <div class='navbar-collapse collapse'>
        <ul class='nav navbar-nav'>
            <li [routerLinkActive]="['link-active']">
                <a [routerLink]="['/home']">
                    <span class='glyphicon glyphicon-home'></span> Home
                </a>
            </li>
            <li [routerLinkActive]="['link-active']">
                <a [routerLink]="['/counter']">
                    <span class='glyphicon glyphicon-education'></span> Counter
                </a>
            </li>
            <li [routerLinkActive]="['link-active']">
                <a [routerLink]="['/fetch-data']">
                    <span class='glyphicon glyphicon-th-list'></span> Fetch data
                </a>
            </li>
            <li [routerLinkActive]="['link-active']">
                <a [routerLink]="['/api/todo']">
                    <span class='glyphicon glyphicon-apple'></span> Todo api
                </a>
            </li>
        </ul>
    </div>
</div>

我的app.component.ts：

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

@Component({
    selector: 'app',templateUrl: './app.component.html',styleUrls: ['./app.component.css']
})
export class AppComponent {
}

这里的问题是,当我单击菜单按钮以获取数据时没有任何反应,所有其他按钮都在工作但不是这个按钮,直接使用浏览器URL时仍然显示200结果.

没有错误消息,我在网上找不到与Angular中的非可点击按钮相关的问题的搜索解决方案,并且无法将数据从ASP.Net传递到Angular.

我究竟做错了什么？