我得到的例外:没有提供Http!我做错了什么?

import {Http, Headers} from 'angular2/http';
import {Injectable} from 'angular2/core'


@Component({
    selector: 'greetings-ac-app2',
    providers: [],
    templateUrl: 'app/greetings-ac2.html',
    directives: [NgFor, NgModel, NgIf, FORM_DIRECTIVES],
    pipes: []
})
export class GreetingsAcApp2 {
    private str:any;

    constructor(http: Http) {

        this.str = {str:'test'};

        http.post('http://localhost:18937/account/registeruiduser/',
            JSON.stringify(this.str),
            {
                headers: new Headers({
                    'Content-Type': 'application/json'
                })
            });

当前回答

从@angular/http导入{HttpModule};打包到模块中。Ts文件并将其添加到导入中。

其他回答

在app.module.ts文件中导入HttpModule。

import { HttpModule } from '@angular/http';
import { YourHttpTestService } from '../services/httpTestService';

还记得在import下面声明HttpModule,如下所示:

imports: [
    BrowserModule,
    HttpModule
  ],

只需包含以下库:

import { HttpModule } from '@angular/http';
import { YourHttpTestService } from '../services/httpTestService';

并在providers部分中包含HTTP类,如下所示:

@Component({
  selector: '...',
  templateUrl: './test.html',
  providers: [YourHttpTestService]

如果在测试中出现此错误,则应该为所有服务创建假服务:

例如:

import { YourService1 } from '@services/your1.service';
import { YourService2 } from '@services/your2.service';

class FakeYour1Service {
 public getSomeData():any { return null; }
}

class FakeYour2Service {
  public getSomeData():any { return null; }
}

在beforeEach中:

beforeEach(async(() => {
  TestBed.configureTestingModule({
    providers: [
      Your1Service,
      Your2Service,
      { provide: Your1Service, useClass: FakeYour1Service },
      { provide: Your2Service, useClass: FakeYour2Service }
    ]
  }).compileComponents();  // compile template and css
}));

最好的方法是通过在providers数组中添加Http来更改组件的装饰器,如下所示。

@Component({
    selector: 'greetings-ac-app2',
    providers: [Http],
    templateUrl: 'app/greetings-ac2.html',
    directives: [NgFor, NgModel, NgIf, FORM_DIRECTIVES],
    pipes: []
})

在2016年9月14日发布的Angular 2.0.0版本中,你仍然在使用HttpModule。你的主app.module.ts看起来是这样的:

import { HttpModule } from '@angular/http';

@NgModule({
   bootstrap: [ AppComponent ],
   declarations: [ AppComponent ],
   imports: [
      BrowserModule,
      HttpModule,
      // ...more modules...
   ],
   providers: [
      // ...providers...
   ]
})
export class AppModule {}

然后在你的app.ts中,你可以这样引导:

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule } from './app/main/app.module';

platformBrowserDynamic().bootstrapModule(AppModule);