angular2 http：帖子拋出錯誤

Question

我正在用angular2開發一個簡單的CRUD應用程序，但無法發布到后端服務器。 我的課程代碼如下

export class PersonForm {
  data:Object;
  loading: boolean;
  personForm: ControlGroup;
  http:Http;
  constructor(personFormBuilder: FormBuilder) {
    this.personForm = personFormBuilder.group({
      'name': [],
      'age': []
    });
  }

  onSubmit(value:any) : void {
    console.log('you submitted these values: ', value);
    this.http.post("http://localhost:3000/people/create",JSON.stringify(value))
      .subscribe((res: Response) => {
        this.data = res.json();
        this.loading = true;
  });

 }

}

以上是在我的控制台中導致以下錯誤的原因。 我不確定到底是什么未定義，因為我正在跟蹤每個我確切找到的示例：

EXCEPTION: Error during evaluation of "ngSubmit"
ORIGINAL EXCEPTION: TypeError: undefined is not an object
(evaluating 'this.http.post')

這是我的進口商品，以防萬一我缺少一個組件

import {Component } from 'angular2/core';
import {bootstrap} from 'angular2/platform/browser';
import {CORE_DIRECTIVES,FORM_DIRECTIVES, FormBuilder} from 'angular2/common';
import {HTTP_PROVIDERS, Http, Response, Headers} from 'angular2/http';
import {ControlGroup} from "angular2/common";

Answer 1

您需要在組件構造函數中注入http對象：

import {Http} from 'angular2/http';

@Component({
  (...)
})
export class PersonForm {
  data:Object;
  loading: boolean;
  personForm: ControlGroup;
  http:Http;

  constructor(private http: Http, personFormBuilder: FormBuilder) {
    (...)
  }
}

希望對您有幫助，蒂埃里