利用YAHOO公开API做天气预报Web服务

 

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>// l.yimg.com/us.yimg.com/i/us/we/52/28.gif" border=0 alt='点击查看大图' onload='javascript:if(this.width>screen.width-450)this.width=screen.width-450'>"/><br />
< 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！