在 c# 中解析天气预报数据（来自 NDFD）

Question

I am using > http://www.weather.gov/forecasts/xml/DWMLgen/wsdl/ndfdXML.wsdl webservice to get the weather detials by calling GmlTimeSeries webmethod. Now I just want to read temparature, weather icon link details from the xml. The xml has huge data. Can anybody give an idea to fetch the required data from the xml?

NDFD HOme Page

The XML looks almost like below: Full XML File is Here

I want to fetch Temparature from below xml data:

 <gml:featureMember>
          <app:Forecast_Gml2Point>
             <gml:position>
                <gml:Point srsName="EPSG:4326">
                   <gml:coordinates>-87.8859170,41.7450495</gml:coordinates>
                </gml:Point>
             </gml:position>
             <app:validTime>2011-06-07T12:00:00</app:validTime>
             <app:temperature>77.0</app:temperature>
          </app:Forecast_Gml2Point>
       </gml:featureMember>

       <gml:featureMember>
          <app:Forecast_Gml2Point>
             <gml:position>
                <gml:Point srsName="EPSG:4326">
                   <gml:coordinates>-87.8859170,41.7450495</gml:coordinates>
                </gml:Point>
             </gml:position>
             <app:validTime>2011-06-07T15:00:00</app:validTime>
             <app:temperature>90.0</app:temperature>
          </app:Forecast_Gml2Point>
       </gml:featureMember>

And weather phrase from below:

 <gml:featureMember>
      <app:Forecast_Gml2Point>
         <gml:position>
            <gml:Point srsName="EPSG:4326">
               <gml:coordinates>-87.8859170,41.7450495</gml:coordinates>
            </gml:Point>
         </gml:position>
         <app:validTime>2011-06-08T03:00:00</app:validTime>
         <app:weatherPhrase>Mostly Clear</app:weatherPhrase>
      </app:Forecast_Gml2Point>
   </gml:featureMember>

   <gml:featureMember>
      <app:Forecast_Gml2Point>
         <gml:position>
            <gml:Point srsName="EPSG:4326">
               <gml:coordinates>-87.8859170,41.7450495</gml:coordinates>
            </gml:Point>
         </gml:position>
         <app:validTime>2011-06-08T06:00:00</app:validTime>
         <app:weatherPhrase>Mostly Clear</app:weatherPhrase>
      </app:Forecast_Gml2Point>
   </gml:featureMember>

The above is a piece of xml file. Like this I have large data for 7 days weather details. I need to read for the temp and weather condition from above xml.

Full XML File is Here

Answer 1

I think you will find your answer here

Edit: you need to use namespace, for example:

XNamespace app = "http://www.weather.gov/forecasts/xml/OGC_services";
var result = from i in doc.Descendants(app+"Forecast_Gml2Point")
                  select new 
                  {
                      temperature = i.Element(app + "temperature"), 
                      icon = i.Element(app+"weatherIcon")
                  };

Edit 2: if you need to get Element with other namespace, here is another example:

XNamespace gml ="http://www.opengis.net/gml"
i.Element(gml+"coordinates" )

Answer 2

It would be easier if you use the "Add Web Reference" feature of Visual Studio. In this way, Visual Studio generates all the (proxy) classes for you base on the WSDL, and you can then program against the classes like how you'll do normally. In other words, there is no parsing of XML needed.

As pointed out in this link :

Visual Studio.Net Web References are proxy classes created on the client to connect to the Web Service running on the server. Inside of the IDE Web references automatically generate code and insert hidden files into your project. This is required because.Net is type safe and in order to compile code that uses the Web Service, the client has to know the method signature of each method that is called.

You might want to refer to the above link about consuming WSDL in details.