在asp.net中 利用雅虎天气API做天气预报功能

出处：http://dotnet.cnblogs.com/page/42993/?page=1

这个功能 主要参考以上文章，同时本人又添加了中文天气显示 和天气图片显示。

雅虎天气的API 详细介绍

http://developer.yahoo.com/weather/

首先了解Yahoo Weather Api的RSS Response格式

例如 成都
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<rss version="2.0" xmlns:yweather="http://xml.weather.yahoo.com/ns/rss/1.0" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#">

<channel>

<title>Yahoo! Weather - Hua-yang, CH</title>

<link>http://us.rd.yahoo.com/dailynews/rss/weather/Hua-yang__CH/*http://weather.yahoo.com/forecast/CHXX0052_f.html</link>

<description>Yahoo! Weather for Hua-yang, CH</description>

<language>en-us</language>

<lastBuildDate>Mon, 24 Oct 2011 1:59 pm CST</lastBuildDate>

<ttl>60</ttl>

<yweather:location city="Hua-yang" region="" country="CH" />

<yweather:units temperature="F" distance="mi" pressure="in" speed="mph" />

<yweather:wind chill="75" direction="120" speed="4" />

<yweather:atmosphere humidity="50" visibility="4.35" pressure="30.09" rising="2" />

<yweather:astronomy sunrise="7:12 am" sunset="6:24 pm" />

<image>

<title>Yahoo! Weather</title>

<width>142</width>

<height>18</height>

<link>http://weather.yahoo.com</link>

<url>http://l.yimg.com/a/i/brand/purplelogo//uh/us/news-wea.gif</url>

</image>

<item>

<title>Conditions for Hua-yang, CH at 1:59 pm CST</title>

<geo:lat>30.5</geo:lat>

<geo:long>104.07</geo:long>

<link>http://us.rd.yahoo.com/dailynews/rss/weather/Hua-yang__CH/*http://weather.yahoo.com/forecast/CHXX0052_f.html</link>

<pubDate>Mon, 24 Oct 2011 1:59 pm CST</pubDate>

<yweather:condition text="Partly Cloudy" code="30" temp="75" date="Mon, 24 Oct 2011 1:59 pm CST" />

<description><![CDATA[

<img src="http://l.yimg.com/a/i/us/we/52/30.gif"/><br />

<b>Current Conditions:</b><br />

Partly Cloudy, 75 F<BR />

<BR /><b>Forecast:</b><BR />

Mon - Partly Cloudy. High: 71 Low: 60<br />

Tue - Showers. High: 65 Low: 58<br />

<br />

<a href="http://us.rd.yahoo.com/dailynews/rss/weather/Hua-yang__CH/*http://weather.yahoo.com/forecast/CHXX0052_f.html">Full Forecast at Yahoo! Weather</a><BR/><BR/>

(provided by <a href="http://www.weather.com" >The Weather Channel</a>)<br/>

]]></description>

<yweather:forecast day="Mon" date="24 Oct 2011" low="60" high="71" text="Partly Cloudy" code="30" />

<yweather:forecast day="Tue" date="25 Oct 2011" low="58" high="65" text="Showers" code="11" />

<guid isPermaLink="false">CHXX0052_2011_10_25_7_00_CST</guid>

</item>

</channel>

</rss>

上面红色的两行，是查询当天和第二天的天气情况，我们要获取的天气信息就在里面

一、首先在vs中建立 web服务。添加代码如下：

public class Weather : System.Web.Services.WebService

{

[WebMethod(Description = "根据城市的名称返回该城市的天气预报情况，只能查询省会和直辖市的天气情况。")]

public DataSet GetWeather(string strCityName)

{

string strXml = "http://xml.weather.yahoo.com/forecastrss?p=CHXX" + CityNameToCityNum(strCityName);

XmlDocument Weather = new XmlDocument();

Weather.Load(strXml);

XmlNamespaceManager namespacemanager = new

XmlNamespaceManager(Weather.NameTable);

namespacemanager.AddNamespace("yweather",

"http://xml.weather.yahoo.com/ns/rss/1.0");

XmlNodeList nodes = Weather.SelectNodes("/rss/channel/item/yweather:forecast", namespacemanager);

//XmlNodeList nodes = Weather.GetElementsByTagName("forecast", "http://xml.weather.yahoo.com/ns/rss/1.0");

DataSet dstWeather = new DataSet();

DataTable dtblWeather = new DataTable("Weather");

dstWeather.Tables.Add(dtblWeather);

dstWeather.Tables["Weather"].Columns.Add("Date", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("Week", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("Weather", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("WeatherCh", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("Tlow", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("Thigh", typeof(string));

dstWeather.Tables["Weather"].Columns.Add("Code", typeof(string));

if (nodes.Count > 0)

{

foreach (XmlNode node in nodes)

{

DataRow drowWeather = dstWeather.Tables["Weather"].NewRow();

drowWeather["Date"] = EmonthToCmonth(node.SelectSingleNode

("@date").Value.ToString());

drowWeather["Week"] = EweekToCweek(node.SelectSingleNode

("@day").Value.ToString()) + "(" + node.SelectSingleNode("@day").Value.ToString()

+ ")";

drowWeather["Weather"] = node.SelectSingleNode("@text").Value;

drowWeather["WeatherCh"] = EN_weather_ch(Convert.ToInt32(node.SelectSingleNode("@code").Value));

drowWeather["Tlow"] = FToC(int.Parse(node.SelectSingleNode

("@low").Value)) + "℃";

drowWeather["Thigh"] = FToC(int.Parse(node.SelectSingleNode

("@high").Value)) + "℃";

drowWeather["Code"] = node.SelectSingleNode("@code").Value;

dstWeather.Tables["Weather"].Rows.Add(drowWeather);

}

return dstWeather;

}

else

{

DataRow drowNone = dstWeather.Tables["Weather"].NewRow();

drowNone["Week"] = "None";

drowNone["Weather"] = "None";

drowNone["Tlow"] = "None";

drowNone["Thigh"] = "None";

dstWeather.Tables["Weather"].Rows.Add(drowNone);

return dstWeather;

}

return dstWeather;

}

/// <summary>

/// 从华氏转换成摄氏

/// </summary>

/// <param name="f">华氏度</param>

/// <returns></returns>

private string FToC(int f)

{

return Math.Round((f - 32) / 1.8, 1).ToString();

}

/// <summary>

/// 从星期英文缩写转汉字

/// </summary>

/// <param name="strEweek">星期的英文缩写</param>

/// <returns></returns>

private string EweekToCweek(string strEweek)

{

switch (strEweek)

{

case "Mon":

return "星期一";

break;

case "Tue":

return "星期二";

break;

case "Wed":

return "星期三";

break;

case "Thu":

return "星期四";

break;

case "Fri":

return "星期五";

break;

case "Sat":

return "星期六";

break;

case "Sun":

return "星期日";

break;

default:

return "传参错误";

break;

}

}

/// <summary>

/// 从月英文缩写转汉字

/// </summary>

/// <param name="strReplace">需要替换的年月日</param>

/// <returns></returns>

private string EmonthToCmonth(string strReplace)

{

return Convert.ToDateTime(strReplace).ToString("yyyy年MM月dd日");

}

/// <summary>

/// 根据城市名称返回城市编号

/// </summary>

/// <param name="strCityName">城市名称</param>

/// <returns></returns>

private string CityNameToCityNum(string strCityNameToNum)

{

//中国各个省会和直辖市对应的查询代码

Hashtable htWeather = new Hashtable();

htWeather.Add("北京", "0008");

htWeather.Add("天津", "0133");

htWeather.Add("杭州", "0044");

htWeather.Add("合肥", "0448");

htWeather.Add("上海", "0116");

htWeather.Add("福州", "0031");

htWeather.Add("重庆", "0017");

htWeather.Add("南昌", "0097");

htWeather.Add("香港", "0049");

htWeather.Add("济南", "0064");

htWeather.Add("澳门", "0512");

htWeather.Add("郑州", "0165");

htWeather.Add("呼和浩特", "0249");

htWeather.Add("乌鲁木齐", "0135");

htWeather.Add("长沙", "0013");

htWeather.Add("银川", "0259");

htWeather.Add("广州", "0037");

htWeather.Add("拉萨", "0080");

htWeather.Add("海口", "0502");

htWeather.Add("南宁", "0100");

htWeather.Add("成都", "0016");

htWeather.Add("石家庄", "0122");

htWeather.Add("贵阳", "0039");

htWeather.Add("太原", "0129");

htWeather.Add("昆明", "0076");

htWeather.Add("沈阳", "0119");

htWeather.Add("西安", "0141");

htWeather.Add("长春", "0010");

htWeather.Add("兰州", "0079");

htWeather.Add("西宁", "0236");

htWeather.Add("南京", "0099");

object cityNum = htWeather[strCityNameToNum];

if (cityNum == null)

{

return "City not found";

}

else

{

return cityNum.ToString();

}

}

/// <summary>

/// 雅虎天气 英文转中文

/// </summary>

/// <param name="code">天气代码</param>

/// <returns></returns>

private string EN_weather_ch(int code)

{

switch (code)

{

case 0: return "龙卷风 ";

case 1: return "热带风暴";

case 2: return "飓风";

case 3: return "严重的雷暴 ";

case 4: return "雷暴 ";

case 5: return "混合雨雪";

case 6: return "混合降雨和冰雹 ";

case 7: return "混合雪和雨夹雪 ";

case 8: return "冻结小雨 ";

case 9: return "小雨 ";

case 10: return "冻雨 ";

case 11:return "阵雨";

case 12: return "阵雨";

case 13:return "雪飘雪";

case 14: return "小雪阵雨";

case 15: return "吹雪";

case 16:return "雪";

case 17:return "冰雹";

case 18:return "雨夹雪";

case 19:return "尘埃";

case 20: return "雾";

case 21:return "霾";

case 22:return "黑烟";

case 23:return "大风";

case 24:return "风";

case 25:return "低温";

case 26:return "多云";

case 27:return "多云（晚上）";

case 28:return "多云（白天）";

case 29:return "局部多云（晚上）";

case 30:return "局部多云（天）";

case 31:return "清爽（晚）";

case 32:return "晴天";

case 33:return "晴朗（晚）";

case 34:return "晴朗（天）";

case 35:return "混合雨和冰雹";

case 36:return "热";

case 37:return "局部地区性雷暴";

case 38:return "零星雷暴";

case 39:return "零星雷暴";

case 40:return "零星阵雨";

case 41:return "大雪";

case 42:return "零星阵雪";

case 43:return "大雪";

case 44:return "多云";

case 45:return "雷阵雨";

case 46:return "阵雪";

case 47:return "局部雷阵雨";

default: return "3200无法使用";

}

}

}

二、调用方法，获取数据

我自己写的代码：

public string today_weather = "";//今天天气

public string today_Hight = "";//今天最高温度

public string today_Low = "";//今天最低温度

public string today_weather_img = "";//天气图片

//明天天气

public string tomorrow_weather = "";//今天天气

public string tomorrow_Hight = "";//今天最高温度

public string tomorrow_Low = "";//今天最低温度

public string tomorrow_weather_img = "";//天气图片

protected void Page_Load(object sender, EventArgs e)

{

Weather _w = new Weather();

DataTable _s=_w.GetWeather("成都").Tables[0];

if (_s.Rows.Count > 0)

{

today_weather = _s.Rows[0]["WeatherCh"].ToString();

today_Hight = _s.Rows[0]["Thigh"].ToString();

today_Low = _s.Rows[0]["Tlow"].ToString();

today_weather_img = "http://l.yimg.com/a/i/us/nws/weather/gr/" + _s.Rows[0]["Code"].ToString() + "n.png";//大图

//小图 "http://l.yimg.com/a/i/us/we/52/" + _s.Rows[1]["Code"].ToString() + ".gif";

tomorrow_weather = _s.Rows[1]["WeatherCh"].ToString();

tomorrow_Hight = _s.Rows[1]["Thigh"].ToString();

tomorrow_Low = _s.Rows[1]["Tlow"].ToString();

tomorrow_weather_img = "http://l.yimg.com/a/i/us/nws/weather/gr/" + _s.Rows[1]["Code"].ToString() + "n.png";//大图

}

}

（1）GetWeather方法是公共方法，提供Web调用。

（2）FToC方法，他主要是把RSS返回的华氏温度转换成摄氏温度，其实这一步可以不用的，当初没发现，URL中加点参数就返回的是摄氏温度。

（3）EweekToCweek方法，他主要是把英文的星期缩写变成中文。

（4）EmonthToCmonth方法，它主要是把英文的月份缩写变成中文，并重新排序。

（5）CityNameToCityNum方法，这个最重要，他是把省会和直辖市的名字转换为编号，因为YAHOO传的参数不是城市名字的区号，全是自己的，而我又想不到更好的获得YAHOO城市对应的编号的方法，所以就只能支持这么几个城市了，希望有高手提出更好的方法，能不用这样，直接找YAHOO获取编号。

(6)EN_weather_ch方法，主要是根据天气代码 获取中文的天气信息。雅虎返回的天气信息是英文的，此处是我在网上找的雅虎天气代码与的中文对应。如有错误请网友指正。共同进步。