Angular学习笔记（二十五）http通讯和webSocket通讯

http通讯

• 发送http请求 参考api文档
• 处理http响应
• 携带请求头部信息

需要注意的是：
get(url: string, options?: RequestOptionsArgs): Observable<Response>
发送http请求返回的是个可观察者流，需要对其进行订阅获取相应消息。

写一个用get方法请求的demo:

stock.component.ts

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

@Component({
  selector: 'app-stock',
  templateUrl: './stock.component.html',
  styleUrls: ['./stock.component.css']
})
export class StockComponent implements OnInit {
   
   

  dataSource:Observable<any>;
  stocks = [];

  constructor(public http:Http) { 
  this.dataSource = this.http.get('/api/stock').map(response => response.json())
  //发送http请求
  }

  ngOnInit() {
   this.dataSource.subscribe(
     data => this.stocks = data
  )
  //订阅流，并将数据赋值给stocks
  }

}

stock.component.html

<div>
股票信息:   
</div>
<ul>
    <li *ngFor