c# - Exception filter not working in web api -

i have custom exception filter capable handle errors in controller( common error handling mechanism) ,

public class exceptionhandlingattribute : exceptionfilterattribute     {         public override void onexception(httpactionexecutedcontext actionexecutedcontext)         {             var error = actionexecutedcontext.exception;             if (error bussinessexcetion)             {                 var exceptionbase = (bussinessexcetion)error;                 var code = (httpstatuscode)exceptionbase.httpexceptioncode;                 throw new httpresponseexception(new httpresponsemessage(code)                                                     {                                                         content = new stringcontent(exceptionbase.message),                                                         reasonphrase = "exception"                                                          ,                                                     });              }              // log error              /* error logging */              loggingfactory.getlogger().logerror(string.format("exception:{0} ||stack trace:{1}", error.message, error.stacktrace), error);                throw new httpresponseexception(new httpresponsemessage(httpstatuscode.internalservererror)                                                 {                                                     content = new stringcontent("an error occurred, contact support team."),                                                     reasonphrase = "critical exception"                                                 });         }     } 

i registered filter in fillterconfig file

 public static void registerglobalfilters(globalfiltercollection filters)     {         filters.add(new exceptionhandlingattribute());      filters.add(new handleerrorattribute());      } 

but getting error

the given filter instance must implement 1 or more of following filter interfaces: iauthorizationfilter, iactionfilter, iresultfilter, iexceptionfilter

i know exceptionfilterattribute implimented iexceptionfilter filter. why getting error

in order work, need implement system.web.http.filters.exceptionfilterattribute.

public class notimplexceptionfilterattribute : exceptionfilterattribute {     log4net.ilog log = log4net.logmanager.getlogger(system.reflection.methodbase.getcurrentmethod().declaringtype);      public override void onexception(httpactionexecutedcontext context)     {         requestdata requestdata = new requestdata(context.request);          log.error("notimplexceptionfilterattribute", context.exception);             context.response = new httpresponsemessage(httpstatuscode.notimplemented);     } } 

then, in webapiconfig.cs, register filter:

public static void register(httpconfiguration config)     {         config.routes.maphttproute(             name: "defaultapi",             routetemplate: "api/{controller}/{count}",             defaults: new { count = routeparameter.optional }         );          config.filters.add(new notimplexceptionfilterattribute());     }