??? 中国天气网提供了一些查询天气的API，访问时返回天气信息的JSON格式数据，解析就可以得到天气信息：
http://www.weather.com.cn/data/sk/101281601.html
http://www.weather.com.cn/data/cityinfo/101281601.html
http://m.weather.com.cn/data/101281601.html
后面一串数字为城市代码。
?返回的utf-8字符串
{"weatherinfo":{"city":"东莞","cityid":"101281601","temp":"22","WD":"东风","WS":"1级","SD":"90%","WSE":"1","time":"08:20","isRadar":"0","Radar":""}}
?所以首先要将城市名转换为城市代码，最简单的办法是通过读取一个文本文件来获取：
格式如：
101010100=北京
101010200=海淀
101010300=朝阳
101010400=顺义
101010500=怀柔
101010600=通州
101010700=昌平
101010800=延庆
101010900=丰台
101011000=石景山
101011100=大兴
?
文本文件和PHP文件放在同一目录下；
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js"></script>
<script src="http://libs.baidu.com/bootstrap/2.0.4/js/bootstrap.min.js"></script>
<link href="http://libs.baidu.com/bootstrap/2.0.4/css/bootstrap.min.css" rel="stylesheet"/>
<title>天气查询简单版</title>
</head>
<body>
<form class="form-horizontal" action="" method="post">
<legend>
Weather
</legend>
<div class="control-group">
<label class="control-label" for="idCity">城市：</label>
<div class="controls">
<input name="city" type="text" name="city" id="idCity" placeholder="请输入城市名字" maxlength="64">
</div>
</div>
<div class="control-group">
<div class="controls">
<button type="submit" class="btn btn-primary" style="margin: 10px">
确定
</button>
<button type="reset" class="btn btn-inverse" style="margin: 10px">
重置
</button>
</div>
</div>
</form>
<hr/>
<?php
header("Content-Type: text/html; charset=utf-8");
function getWeather($city) {
$wcity = file_get_contents("wcity.txt");
$pattern = '/([0-9]+)=' . $city . '/';
preg_match($pattern, $wcity, $matches, PREG_OFFSET_CAPTURE);
if ($matches == null) {
return null;
}
$cityID = $matches[1][0];
$data = file_get_contents('http://www.weather.com.cn/data/sk/' . $cityID . '.html');
return json_decode($data, true);
}
if ($_POST != null && $_POST["city"] != null) {
$weather = getWeather($_POST["city"]);
if ($weather == null) {?>
<div class="alert alert-block" style="margin: 20px">
<button type="button" class="close" data-dismiss="alert">
×
</button>
<h4>警告!</h4>
发生错误了亲，您输入的城市好像没有找到哦！
</div>
<?php return;
}
$info = $weather["weatherinfo"];
?>
<table class="table table-striped table-bordered" style="margin-left: 20px;width: 200px">
<thead>
<th>实时天气信息</th>
</thead>
<tbody>
<?php
echo "<tr><td>城市：</td><td>".$info["city"]."</td></tr>";
echo "<tr><td>城市ID：</td><td>".$info["cityid"]."</td></tr>";
echo "<tr><td>气温：</td><td>".$info["temp"]."℃</td></tr>";
echo "<tr><td>风向：</td><td>".$info["WD"]."</td></tr>";
echo "<tr><td>风力：</td><td>".$info["WS"]."</td></tr>";
echo "<tr><td>湿度：</td><td>".$info["SD"]."</td></tr>";
echo "<tr><td>更新时间：</
