add namespace using xmlnamespacemanager in C#

Question

I am trying to read the data from XML File. In this elements are prefixed with 'app' and 'gml' text. because of these prefixes I am unable to read the data. For this I am trying to add namespace by using XMLNamespaceManager but not getting.

Edit:

        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load(new StringReader(strResult));
        NameTable nt = new NameTable();
        XmlNamespaceManager prefix = new XmlNamespaceManager(nt);
        string nmspc = xmlDoc.DocumentElement.NamespaceURI;
        prefix.AddNamespace("app:",xmlDoc.DocumentElement.NamespaceURI);

        prefix.PushScope();

Here the strResult contains XML Data

Answer 1

Something like:

var doc = new XmlDocument();
doc.Load(source);
var nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("app", "http://www.weather.gov/forecasts/xml/OGC_services");
var firstPoint = doc.SelectSingleNode("//app:Forecast_Gml2Point", nsmgr);

Note that the namespace aliases are merely conveniences, and don't have to match between the document and the namespace-manager - but it is probably easier if they do.

Answer 2

You could use LINQ-to-XML, like this:

var document = XDocument.Load("http://www.weather.gov/forecasts/xml/SOAP_server/ndfdXMLclient.php?whichClient=GmlLatLonList&lat=&lon=&listLatLon=&lat1=&lon1=&lat2=&lon2=&resolutionSub=&listLat1=&listLon1=&listLat2=&listLon2=&resolutionList=&endPoint1Lat=&endPoint1Lon=&endPoint2Lat=&endPoint2Lon=&listEndPoint1Lat=&listEndPoint1Lon=&listEndPoint2Lat=&listEndPoint2Lon=&zipCodeList=&listZipCodeList=&centerPointLat=&centerPointLon=&distanceLat=&distanceLon=&resolutionSquare=&listCenterPointLat=&listCenterPointLon=&listDistanceLat=&listDistanceLon=&listResolutionSquare=&citiesLevel=&listCitiesLevel=&sector=&gmlListLatLon=38.99,-77.02%2039.70,-104.80%2047.6,-122.30&featureType=Forecast_Gml2Point&requestedTime=&startTime=2000-01-01T00:00:00&endTime=2012-01-01T00:00:00&compType=Between&propertyName=wx,temp,icons&product=time-series&begin=2004-01-01T00:00:00&end=2015-06-07T00:00:00&maxt=maxt&Submit=Submit");
var appSampleElements = document.Descendants(XName.Get("Forecast_Gml2Point", "http://www.weather.gov/forecasts/xml/OGC_services")).ToList();
var gmlSampleElements = document.Descendants(XName.Get("Box", "http://www.opengis.net/gml")).ToList();

Use "http://www.weather.gov/forecasts/xml/OGC_services" namespace for those that prefixed with app. Use "http://www.opengis.net/gml" namespace for those that prefixed with gml.

With XmlDocument:

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("http://www.weather.gov/forecasts/xml/SOAP_server/ndfdXMLclient.php?whichClient=GmlLatLonList&lat=&lon=&listLatLon=&lat1=&lon1=&lat2=&lon2=&resolutionSub=&listLat1=&listLon1=&listLat2=&listLon2=&resolutionList=&endPoint1Lat=&endPoint1Lon=&endPoint2Lat=&endPoint2Lon=&listEndPoint1Lat=&listEndPoint1Lon=&listEndPoint2Lat=&listEndPoint2Lon=&zipCodeList=&listZipCodeList=&centerPointLat=&centerPointLon=&distanceLat=&distanceLon=&resolutionSquare=&listCenterPointLat=&listCenterPointLon=&listDistanceLat=&listDistanceLon=&listResolutionSquare=&citiesLevel=&listCitiesLevel=&sector=&gmlListLatLon=38.99,-77.02%2039.70,-104.80%2047.6,-122.30&featureType=Forecast_Gml2Point&requestedTime=&startTime=2000-01-01T00:00:00&endTime=2012-01-01T00:00:00&compType=Between&propertyName=wx,temp,icons&product=time-series&begin=2004-01-01T00:00:00&end=2015-06-07T00:00:00&maxt=maxt&Submit=Submit");
XmlNamespaceManager namespaceManager = new XmlNamespaceManager(xmlDoc.NameTable);
namespaceManager.AddNamespace("app", "http://www.weather.gov/forecasts/xml/OGC_services");
namespaceManager.AddNamespace("gml", "http://www.opengis.net/gml");

var appNodes = xmlDoc.SelectNodes("//app:Forecast_Gml2Point", namespaceManager);
var gmlNode = xmlDoc.SelectSingleNode("//gml:Box", namespaceManager);