c# - 400 error from webservice -

can explain me why im getting http 400 error when trying post webservice?

my service contract ::

[servicecontract] public interface ifldtwholesaleservice {     [operationcontract]     [webinvoke(method = "post",         responseformat = webmessageformat.xml,         bodystyle = webmessagebodystyle.wrapped,         uritemplate = "mac")]     string mac(string input); 

my call;

    private void posttowebsite()     {         httpwebrequest req = (httpwebrequest)httpwebrequest.create(txturl.text);         req.method = "post";         req.mediatype = "text/xml";           string input = "dfwa";         req.contentlength = asciiencoding.utf8.getbytecount(input);          streamwriter writer = new streamwriter(req.getrequeststream());         writer.write(input);         writer.close();         var rsp = req.getresponse().getresponsestream();          txtout.text = new streamreader(rsp).readtoend();     } 

my server config file

<system.servicemodel>     <services>         <service name="fldtrestwebservice.fldtwholesaleservice" behaviorconfiguration="httpbehaviour">             <endpoint address="" binding="webhttpbinding" contract="fldtrestwebservice.ifldtwholesaleservice" behaviorconfiguration="httpendpointbehavour">                 <identity>                     <dns value="localhost"/>                 </identity>             </endpoint>             <endpoint address="mex" binding="mexhttpbinding" contract="imetadataexchange"/>             <host>                 <baseaddresses>                     <add baseaddress="http://localhost:8080/contactservice/"/>                 </baseaddresses>             </host>         </service>     </services>     <behaviors>         <servicebehaviors>             <behavior name="httpbehaviour">                 <servicemetadata httpgetenabled="true"/>                 <servicedebug includeexceptiondetailinfaults="false"/>             </behavior>         </servicebehaviors>         <endpointbehaviors>             <behavior name="httpendpointbehavour">                 <webhttp/>             </behavior>         </endpointbehaviors>     </behaviors> </system.servicemodel> 

edit :: gives same error when using mediatype "text/plain"

an endpoint webhttpbinding / webhttp behavior default accepts requests in either xml or json format. , xml send needs conform service expects. code below sends request service expects. also, notice need set contenttype property on httpwebrequest, not mediatype.

public class stackoverflow_6550019 {     [servicecontract]     public interface ifldtwholesaleservice     {         [operationcontract]         [webinvoke(method = "post",             responseformat = webmessageformat.xml,             bodystyle = webmessagebodystyle.wrapped,             uritemplate = "mac")]         string mac(string input);     }      public class service : ifldtwholesaleservice     {         public string mac(string input)         {             return input;         }     }      private static void posttowebsite(string url)     {         httpwebrequest req = (httpwebrequest)httpwebrequest.create(url);         req.method = "post";         req.contenttype = "text/xml";          string input = @"<mac xmlns=""http://tempuri.org/""><input>hello</input></mac>";          streamwriter writer = new streamwriter(req.getrequeststream());         writer.write(input);         writer.close();         var rsp = req.getresponse().getresponsestream();          console.writeline(new streamreader(rsp).readtoend());     }      public static void test()     {         string baseaddress = "http://" + environment.machinename + ":8000/service/";         webservicehost host = new webservicehost(typeof(service), new uri(baseaddress));         host.open();         console.writeline("host opened");          // find out expected request, using wcf client. @ sends in fiddler         var factory = new webchannelfactory<ifldtwholesaleservice>(new uri(baseaddress));         var proxy = factory.createchannel();         proxy.mac("hello world");          posttowebsite(baseaddress + "/mac");          console.write("press enter close host");         console.readline();         host.close();     } }