Angular2 原始例外:this.http.post 不是一个函数

Question

import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
// import 'rxjs/add/operator/toPromise';

@Injectable()
export class AccessService {
private baseUrl = '';
constructor(private http: Http) {
}
login(email: string, password: string) {
    //      var loginUrl = 'http://localhost:8000/app.php/api/login_check';  // url to web API
    var loginUrl = this.baseUrl + 'api/login_check';  // url to web API
    let user = JSON.stringify({ _username: email, _password: password });
    console.log(user);
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http
        .post(loginUrl, user, options)
        .map(this.extractData)
        .catch(this.handleError);
}
register(email: string, password: string, password2: string) {
    var loginUrl = this.baseUrl + 'register/';  // url to web API
    var fos_user_registration_form = {
        username: email,
        email: email,
        plainPassword: { first: password, second: password2 },
        roles: ['ROLE_CLIENT']
    };
    let user = JSON.stringify({
        fos_user_registration_form
    });
    console.log(user);
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });
    if (password === password2) {
        return this.http
            .post(loginUrl, user, options)
            .map(this.extractData)
            .catch(this.handleError);
    } else {
        alert('Las Contraseñas No Coinciden');
    }
}
private extractData(res: Response) {
    let body = res.json();
    console.log(body);
    return body.data || {};
}
private handleError(error: Response | any) {
    // in a real world app, we might use a remote logging infrastructure
    let errMsg: string;
    if (error instanceof Response) {
        const body = error.json() || '';
        const err = body.error || JSON.stringify(body);
        errMsg = `${error.status} - ${error.statusText || ''} ${err}`;
    } else {
        errMsg = error.message ? error.message : error.toString();
    }
    console.error(errMsg.toString());
    return Observable.throw(errMsg);
}

我试图用角度 2 制作一个简单的帖子，但返回此异常异常：this.http.post 不是函数，我不确定这是错误的，请帮助我。在它起作用之前，但我在另一个文件夹中克隆了该项目，这对我不起作用。

Answer 1

很可能

您没有在app.module.ts(或这是其中的任何模块(中提供HttpModule。确保您具备以下条件：

import { HttpModule } from '@angular/http';
@NgModule({
  declarations: [
    ....
  ],
  imports: [
    HttpModule,
    ...
  ],
  ...
});