httpwebrequest - Using HttpRequestHeaders in WinRT & C# -

i'm using httpwebrequests contact api , need add header compiler tells me method not exists. yet, when check msdn, tells me method exists. setting useragent-property fails well.

can me please?

try{      httpwebrequest wr = (httpwebrequest)httpwebrequest.create(url);      wr.method = "get";       wr.headers.add(system.net.httprequestheader.authorization, string.format("bearer {0}", _accesstoken));      wr.useragent = _appnameandcontact;       var resp = (system.net.httpwebresponse) await wr.bettergetresponse();      if (resp.statuscode == system.net.httpstatuscode.ok)      {         using (var sw = new system.io.streamreader(resp.getresponsestream()))         {              var msg = sw.readtoend();               user usr = jsonconvert.deserializeobject<user>(msg);                //var results = jsonhelper.deserialize<user>(msg);                return usr;               }         } } 

you have use httprequestmessage this:

  using (var httpclient = new httpclient())   {     var url = new uri("http://bing.com");     var accesstoken = "1234";     using (var httprequestmessage = new httprequestmessage(httpmethod.get, url))     {       httprequestmessage.headers.add(system.net.httprequestheader.authorization.tostring(),         string.format("bearer {0}", accesstoken));       httprequestmessage.headers.add("user-agent", "my user-agent");       using (var httpresponsemessage = await httpclient.sendasync(httprequestmessage))       {         // response         var data = httprequestmessage.content;       }     }   }