用php来写一个天气预报的模块

天气数据是通过采集中国气象网站的。本来中国天气网站也给出了数据的API接口。以下是API的地址。返回的数据格式为json格式。

1. http://www.weather.com.cn/data/sk/101010100.html

2. http://www.weather.com.cn/data/cityinfo/101010100.html

3. http://m.weather.com.cn/data/101010100.html

URL中的数字”101010100“是城市代码。所以可以先列出每个城市的城市代码，然后php程序接收到了城市代码，再去组装URL，在通过URL来显示该城市的实时天气。

index.php

header("Content-Type:text/html;charset=utf-8");

?>

weather forecast

function $(id){

return document.getElementById(id);

}

function getCityId(){

var http_request=createAjax();

var url="weatherforecast.php"

var data="cityid="+$("cityId").value;

http_request.onreadystatechange=getWetherInfo;

http_request.open("post",url,true);

http_request.setRequestHeader("Content-type","application/x-www-form-urlencoded");

http_request.send(data);

function getWetherInfo(){

if(http_request.readyState==4 && http_request.status==200){

var info=http_request.responseText;

$("weatherinfo").innerHTML=info;

}

}

}

--请选择城市--

北京

上海

天津

重庆

广州

weatherforecast.php

header("Content-Type:text/html;charset=utf-8");

header("Cache-Control:no-cache");

if (isset($_POST['cityid'])){

$cityid=$_POST['cityid'];

$url=$url="http://www.weather.com.cn/data/sk/".$cityid.".html";

}else {

$url="http://www.weather.com.cn/data/sk/101010100.html";

}

$weatherInfo_json=file_get_contents($url);

$weatherInfo=json_decode($weatherInfo_json,true);

$cityName=$weatherInfo['weatherinfo']['city'];

$cityTemp=$weatherInfo['weatherinfo']['temp'];

$cityWd=$weatherInfo['weatherinfo']['WD'];

$cityWs=$weatherInfo['weatherinfo']['WS'];

$cityTime=$weatherInfo['weatherinfo']['time'];

$citySD=$weatherInfo['weatherinfo']['SD'];

echo $weatherinfo="城市名字：$cityName,气温：$cityTemp,风向：$cityWd";

?>