dotnetrdf - Why does my SPARQL query return the URI of a resource instead of its name? -

i want classes of ontology. part of ontology file in rdf/xml format created protege:

<!-- http://www.w3.org/2002/07/owl#aqua -->  <class rdf:about="&owl;aqua"/>  <!-- http://www.w3.org/2002/07/owl#varioperfect -->  <class rdf:about="&owl;varioperfect"/> 

i wrote query, works in protege, when use in dotnetrdf returns full uri of class instead of name.

 public string[] ontologysearch() {     list<string> list = new list<string>();     triplestore store = new triplestore();     graph mygraph = new graph();     mygraph.loadfromfile("d:/msc/search-engine/project/catalogxml.owl");         store.add(mygraph);         string sparqlquery1 = "prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>"           + "prefix owl: <http://www.w3.org/2002/07/owl#>"           + "prefix xsd: <http://www.w3.org/2001/xmlschema#>"           + "prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>"           + "select distinct ?cls1"           + " where{"           + "  ?cls1 owl:class .}";        sparqlqueryparser sparqlparser = new sparqlqueryparser();       sparqlquery query = sparqlparser.parsefromstring(sparqlquery1);       inmemorydataset ds = new inmemorydataset(mygraph);        //get query processor       isparqlqueryprocessor processor = new leviathanqueryprocessor(ds);       object results = processor.processquery(query);       if (results sparqlresultset)       {           sparqlresultset r = results sparqlresultset;            foreach (sparqlresult res in r)           {                list.add(res["cls1"].tostring());           }       }        return list.toarray(); 

}

the result expected "aqua" in fact "http://www.w3.org/2002/07/owl#aqua". why happen, , how can retrieve name instead?

non-anonymous resources in rdf , owl identified iris. ontology says http://www.w3.org/2002/07/owl#aqua class. if ask class, that's should get. might protege strips off http://www.w3.org/2002/07/owl# part when displays result, result still iri.

note: should not defining new classes iris begin standard owl namespace. should defining own prefix, typically related ontology iri.

if want string "aqua" result, have 2 options. first (and preferred) approach retrieve rdfs:label of class, if has one, should string name of class. if reason doesn't work, can take string value of uri , strip off string value of prefix. here examples of both approaches on dbpedia sparql endpoint:

select ?class ?label {   ?class owl:class ; rdfs:label ?label   filter langmatches(lang(?label),'en') } limit 10 

sparql results (with rdfs:label)

select ?class ?name {   ?class owl:class   bind(strafter(str(?class),str(dbpedia-owl:)) ?name) } limit 10 

sparql results (by stripping prefix)

stripping off prefix of uri display purposes is, in general, not recommended practice, assumes uri has human-readable form. in case of dbpedia happens work, plenty of datasets have uris internal codes rather human-readable names. if rdfs:label (which explicitly defined human-readable representation of resource) available, should try , use that.