c# - System.Net.Http: missing from namespace? (using .net 4.5) -

tl; dr: i'm new language , have no idea i'm doing

here class far:

using system; using system.collections.generic; using system.net.http; using system.web; using system.net; using system.io;  public class myclass     {         private const string url = "https://sub.domain.com/objects.json?api_key=123";         private const string data = @"{""object"":{""name"":""title""}}";          public static void createobject()         {             httpwebrequest request = (httpwebrequest)webrequest.create(url);             request.method = "post";             request.contenttype = "application/json";             request.contentlength = data.length;             streamwriter requestwriter = new streamwriter(request.getrequeststream(), system.text.encoding.ascii);             requestwriter.write(data);             requestwriter.close();              try             {                 // response                 webresponse webresponse = request.getresponse();                 stream webstream = webresponse.getresponsestream();                 streamreader responsereader = new streamreader(webstream);                 string response = responsereader.readtoend();                 responsereader.close();             }             catch (webexception we)             {                 string webexceptionmessage = we.message;             }             catch (exception ex)             {                 // no need special here....             }         }          static void main(string[] args)         {             myclass.createobject();         } } 

when csc filename.cs, following error:

the type or namespace name 'http' not exist in namespace 'system.net' (are missing assembly reference?)

httpclient lives in system.net.http namespace.

you'll need add:

using system.net.http; 

and make sure referencing system.net.http.dll in .net 4.5.

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the code posted doesn't appear webclient. there wrong code compiling using httpwebrequest?

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update

to open add reference dialog right-click on project in solution explorer , select add reference.... should like: