Angular 2：我想获取聊天消息，但是当我使用可观察的计时器时我得到了错误

Question

我想在服务器1秒后自动获取聊天但是当我使用可观察计时器时出错，请建议我。  我在控制台中遇到的错误在引号中： -

" Response {_body: ProgressEvent, status: 0, ok: false, statusText: "", headers: Headers…} "

这是我在angular 2.0中使用的代码，在函数ngOnInit中我使用的计时器在控制台中几秒后就给我发错了。

import { Component, OnInit } from '@angular/core';
import { Response } from "@angular/http";
import { NgForm } from "@angular/forms";
import {Observable} from 'rxjs/Rx';


import { Chat } from "../chat.interface";
import { ChatService } from '../chat.service';

@Component({
  selector: 'app-chat-box',
  templateUrl: './chat-box.component.html',
  styleUrls: ['./chat-box.component.css'],
  providers: [ChatService]
})

export class ChatBoxComponent implements OnInit {
  thumb="http://www.lovemarks.com/wp-content/uploads/profile-avatars/default-avatar.png";
  data = [];
  messages = [];
  error ='';
  constructor(private chatService: ChatService) {

  }
  ngOnInit() {
    let timer = Observable.timer(10, 500);
    timer.subscribe(() => this.newMessage());
  }
  bubble(){
    this.chatService.getMessages()
    .subscribe(
      (data) => this.data = this.data,
      (error: Response) => console.log(error)
    );
  }
  newMessage(){
    this.chatService.checkMessages()
        .subscribe(
          (data) => this.messages = this.messages.concat(data.messages),
          (error: Response) => console.log(error)
        );
  }
  onSubmit(form: NgForm) {
    this.chatService.createMessage(form.value.message)
      .subscribe(
        () => this.newMessage()
      );
    form.reset();
  }

}