angular2-http

• 提供HTTP服务
  
  • http是angular的HTTP库所提供的一系列服务之一

import { Http, Response, Headers, RequestOptions} from '@angular/http';

• 注册http服务：把HttpModule添加到AppModule的imports列表中

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule } from '@angular/http';

import { AppComponent }  from './app.component';
@NgModule({
    imports: [ 
        BrowserModule, 
        HttpModule
    ],
    declarations: [ 
        AppComponent
    ],
    bootstrap: [ 
        AppComponent 
    ],
    exports: []
})
export class AppModule { }

• 使用http.get()获取数据

getHeroes(): Promise<Hero[]> {
    return this.http.get(requestUrl)
               .toPromise()
               .then(response => response.json().data as Hero[])
               .catch(this.handleError);
  }

• 处理响应对象

//从返回的response中提取数据，通过then的方式提取
.then(response => response.json().data as Hero[])