学了一段时间的Web服务，今天做了一个Web服务，利用YAHOO的公开天气API做自己的Web服务，主要是想练练手。现在把过程和心得分享给大家。
求教：这个Web服务还有个不完善的地方，Web服务的 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，所以就创建了HASHTABLE存储了中国的各个省会城市和直辖市，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，提取更多的城市，而不用把所有的中国所有的城市全写在HASHTABLE里。
Web服务地址：http://www.h2bbs.com/Weather/Weather.asmx
原理：
在Yahoo的Developer Network
http://developer.yahoo.com/weather/
详细地介绍了Yahoo天气预报的API调用方法，这里用C#来实现，本文主要是利用它的API做Web服务，其它的应用由网友们自由发挥
首先了解Yahoo Weather Api的RSS Response格式(这是下午我查我家银川天气时返回的RSS)：
<?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 - Yinchuan, CH</title> <link>http://us.rd.yahoo.com/dailynews/rss/weather/Yinchuan__CH/*http://kb.cnblogs.com/page/42993/%3C/span%3E%3Cspan%20style=" target=_blank>http://kb.cnblogs.com/page/42993/%3C/span%3E%3Cspan%20style=</link> <description>Yahoo! Weather for Yinchuan, CH</description> <language>en-us</language> <lastBuildDate>Tue, 14 Oct 2008 11:00 am CST</lastBuildDate> <ttl>60</ttl> <yweather:location city="Yinchuan" region="" country="CH"/> <yweather:units temperature="F" distance="mi" pressure="in" speed="mph"/> <yweather:wind chill="56" direction="360" speed="4" /> <yweather:atmosphere humidity="56" visibility="999" pressure="" rising="0" /> <yweather:astronomy sunrise="7:03 am" sunset="6:19 pm"/> <image> <title>Yahoo! Weather</title> <width>142</width> <height>18</height> <link>http://weather.yahoo.com</link> <url>http://l.yimg.com/us.yimg.com/i/us/nws/th/main_142b.gif</url> </image> <item> <title>Conditions for Yinchuan, CH at 11:00 am CST</title> <geo:lat>38.48</geo:lat> <geo:long>106.22</geo:long> <link>http://us.rd.yahoo.com/dailynews/rss/weather/Yinchuan__CH/*http://kb.cnblogs.com/page/42993/%3C/span%3E%3Cspan%20style=" target=_blank>http://kb.cnblogs.com/page/42993/%3C/span%3E%3Cspan%20style=</link> <pubDate>Tue, 14 Oct 2008 11:00 am CST</pubDate> <yweather:condition text="Mostly Cloudy" code="28" temp="56" date="Tue, 14 Oct 2008 11:00 am CST" />
<description> <![CDATA[<img src="//l.yimg.com/us.yimg.com/i/us/we/52/28.gif" target=_blank><b>Current Conditions:</b><br />Mostly Cloudy, 56 F<BR /><BR /><b>Forecast:</b><BR />Tue - Mostly Cloudy. High: 68 Low: 47<br />Wed - Partly Cloudy. High: 70 Low: 44<br /><br /><a href="Full'>http://us.rd.yahoo.com/dailynews/rss/weather/Yinchuan__CH/*http://weather.yahoo.com/forecast/CHXX0259_f.html">Full Forecast at Yahoo! Weather</a><BR/>(provided by The Weather Channel)<br/>]]> </description> <yweather:forecast day="Tue" date="14 Oct 2008" low="47" high="68" text="Mostly Cloudy" code="28" />
<yweather:forecast day="Wed" date="15 Oct 2008" low="44" high="70" text="Partly Cloudy" code="30" />
<guid isPermaLink="false">CHXX0259_2008_10_14_11_00_CST</guid> </item> </channel></rss><!-- api5.weather.sp1.yahoo.com compressed/chunked Mon Oct 13 22:30:39 PDT 2008 -->
其中最重要的是后面的几行，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，代码如下：
<yweather:forecast day="Tue" date="14 Oct 2008" low="47" high="68" text="Mostly Cloudy" code="28" />
<yweather:forecast day="Wed" date="15 Oct 2008" low="44" high="70" text="Partly Cloudy" code="30" />
我们所需要用到的Node是/rss/channel/item/yweather: forecast；这个节点里的东西是我们需要的。
知道了这些，我们接下来要做的就是在VS中建立WEB服务，并添加下面的代码：
namespace Weather
{
/// <summary>
/// Weather 的摘要说明
/// </summary> [WebService(Name = "天气预报Web服务", Namespace = "http://www.h2bbs.com/WebService/Weather.asmx", Description = "利用YAHOO公开的API接口，在Web服务实现公开的天气预报调用服务。")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] [ToolboxItem(false)] 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("Tlow", typeof(string)); dstWeather.Tables["Weather"].Columns.Add("Thigh", 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["Tlow"] = FToC(int.Parse(node.SelectSingleNode("@low").Value)) + "℃";
drowWeather["Thigh"] = FToC(int.Parse(node.SelectSingleNode("@high").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(); } } }
}
别忘了"using System.Xml;"哦！
Web服务的代码中有一个Web公开方法，四个私有方法：
（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。
查询个中国随便的省会，效果如下
<?xml version="1.0" encoding="utf-8" ?> - <DataSet xmlns="http://www.h2bbs.com/WebService/Weather.asmx">- <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">- <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
- <xs:complexType>- <xs:choice minOccurs="0" maxOccurs="unbounded">- <xs:element name="Weather">- <xs:complexType>- <xs:sequence> <xs:element name="Date" type="xs:string" minOccurs="0" /> <xs:element name="Week" type="xs:string" minOccurs="0" /> <xs:element name="Weather" type="xs:string" minOccurs="0" /> <xs:element name="Tlow" type="xs:string" minOccurs="0" /> <xs:element name="Thigh" type="xs:string" minOccurs="0" /> </xs:sequence> </xs:complexType> </xs:element> </xs:choice> </xs:complexType> </xs:element> </xs:schema>- <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">- <NewDataSet xmlns="">- <Weather diffgr:id="Weather1" msdata:rowOrder="0" diffgr:hasChanges="inserted"> <Date>2008年10月14日</Date> <Week>星期二(Tue)</Week> <Weather>Clear</Weather> <Tlow>16.1℃</Tlow> <Thigh>26.7℃</Thigh> </Weather>- <Weather diffgr:id="Weather2" msdata:rowOrder="1" diffgr:hasChanges="inserted">
<Date>2008年10月15日</Date> <Week>星期三(Wed)</Week> <Weather>Sunny</Weather> <Tlow>16.7℃</Tlow> <Thigh>28.3℃</Thigh> </Weather> </NewDataSet> </diffgr:diffgram> </DataSet>
写完了！最后希望能给大家带来收获！
