ng4.x http数据请求 --- 不用RxJS
【此例通过Http、Jsonp请求数据 ---- 不用RxJS】
【RxJS：是一种针对异步数据流编程工具，或者叫响应式扩展编程；---- 异步编程】
《app.module.ts》: ---- 数据请求模块 的引入及依赖注入
import { HttpModule, JsonpModule } from '@angular/http';
... ...
imports:[
... ...
HttpModule,
JsonpModule ]
《news.component.html》:
<button (click) = "requestData()">请求数据</button>
<ul >
<li *ngFor="let item list"> {{item.title}}</li>
</ul>
法1：--- get请求
《news.component.ts》:
import { Http } from '@angular/http';
export class NewsComponent implements OnInit {
public list :any[];
constructor(private http:Http){}
}
ngOnInit() { }
requestData() {
var _that = this;
var url = "http://www.phonegap100.com/appapi.php?a=getPortallList&catid=20&page=1";
this.http.get(url).subscribe( function (data){
var list = _that.list = JSON.parse(data['_body']);
_that.list = list['result'];
},function(err){
alert(err);
})
}
法2：--- jsonp请求 --- 后台不允许跨域
《news.component.ts》:
import { Http, Jsonp } from '@angular/http';
export class NewsComponent implements OnInit {
public list :any[];
constructor(private http:Http,private jsonp:Jsonp){}
}
ngOnInit() { }
requestData() {
var _that = this;
var url = "http://127.0.0.1:3000/news?&callback=JSONP_CALLBACK";
this.jsonp.get(url).subscribe( function (data){
_that.list =data['_body']['result'];
},function(err){
alert(err);
})
}
nodejs 后台接口：
《app.js》:
var express = require('express');
var app=express();
var bodyParser = require('body-parser');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.get('/news',function(req,res){
res.jsonp({"msg":'这是后台返回的新闻数据'});
})
app.listen(3000,'127.0.0.1');
法3：--- post请求
《news.component.ts》:
import { Http,Headers } from '@angular/http';
export class NewsComponent implements OnInit {
private headers = new Headers({'Content-Type' : 'application/json'});
//设置请求头
public list :any[];
constructor(private http:Http){}
}
ngOnInit() { }
postData() {
var _that = this;
var url = "http://127.0.0.1:3000/dologin";
this.http.post(url,
JSON.stringify({ "username":'xj'}),
{headers:this.hraders}).subscribe(function(data){
console.log(data.json());
},function(err){
alert(err);
})
}
