PHP+AJAX无刷新实现返回天气预报数据

  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

  

复制代码 代码如下:

  <?php

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

  ?>

  <html>

  <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />

  <head>

  <title>weather forecast</title>

  <script type="text/javascript" src="ajax.js"></script>

  <script type="text/javascript">

  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;

  }

  }

  }

  </script>

  </head>

  <body>

  <select name="cityId" onchange="getCityId();" id="cityId">

  <option>--请选择城市--</option>

  <option value="101010100">北京</option>

  <option value="101020100">上海</option>

  <option value="101030100">天津</option>

  <option value="101040100">重庆</option>

  <option value="101280101">广州</option>

  </select>

  <span id="weatherinfo"></span>

  </body>

  </html>

  weatherforecast.php

  

复制代码 代码如下:

  <?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";

  ?>