c# - Web Api controller thinks it is duplicated -

i have webforms app, has web api controllers in integrations. 2 working fine. today wanted add controller.

should simple enough, add new web api controller, add little bit of code it, and:

namespace myapp.web.app_code {     public class authexportcontroller : apicontroller     {         public ienumerable<string> get()         {             return new string[] { "value1", "value2" };         }     }  } 

and when call @ url :

http://localhost:30978/myapp/api/authexport 

i error:

<error>     <message>an error has occurred.</message>     <exceptionmessage>multiple types found match controller named       'authexport'. can happen if route services request       ('api/{controller}/{id}') found multiple controllers defined same name      differing namespaces, not supported. request 'authexport' has found      following matching controllers: myapp.web.app_code.authexportcontroller       myapp.web.app_code.authexportcontroller</exceptionmessage>      <exceptiontype>system.invalidoperationexception</exceptiontype>      <stacktrace> @       system.web.http.dispatcher.defaulthttpcontrollerselector.selectcontroller(httprequestmessag     e request) @        system.web.http.dispatcher.httpcontrollerdispatcher.sendasyncinternal(httprequestmessage      request, cancellationtoken cancellationtoken) @      system.web.http.dispatcher.httpcontrollerdispatcher.sendasync(httprequestmessage       request, cancellationtoken cancellationtoken)</stacktrace> </error> 

as can see, complaining 2 controllers same name, exact same controller. other controllers work fine, particular one.

if helps anything, routing code in global.asax

protected void application_start(object sender, eventargs e) {     routetable.routes.maphttproute(         name: "defaultapi",         routetemplate: "api/{controller}/{id}",         defaults: new { id = system.web.http.routeparameter.optional }     );      globalconfiguration.configuration.formatters.clear();     globalconfiguration.configuration.formatters.add(new xmlmediatypeformatter()); } 

driving me mad!

update:

ok managed fix it, don't understand why, if explain me. compared working controllers non working one. exact same signatures exactly, nothing different, same using statements, same inheritance etc etc. 1 thing did notice build action on file. working file has build action of "content" , non working has build action of "compile" . change non working 1 "content" , works.

so more confused :) happy works, don't black magic in systems

tl;dr:

delete bin folder in projects' file directory , build project again.

explanation:

i encountered error while renaming existing project , changing namespaces , happened:

let's projects' name firstname , wanted rename secondname.

• i built project compiled , generated bin/debug/firstname.dll files
• i renamed project secondname
• i refactored namespace
• built , ran project
• this generated bin/debug/secondname.dll

when project ran, iis express took of .dll files , loaded them memory, happened include both firstname.dll , secondname.dll.

as might understood, firstname.dll , secondname.dll had same classes , methods, different namespaces! therefore, both of dlls loaded memory iis, webapi routing mechanism finding both of namespaces same controllers , action names.

and there have it. no voodoo magic after :)