摘要：主要是利用Http发送请求获得指定城市编号的天气实况等信息。

如 a.假如发送这个请求：http://www.weather.com.cn/data/cityinfo/101190101.html

使用 http，去发送的话 则返回的Json如下：

{"weatherinfo":{"city":"南京","cityid":"101190101","temp1":"15℃","temp2":"10℃","weather":"小雨","img1":"d7.gif","img2":"n7.gif","ptime":"08:00"}}