DELETE method .NET WebAPI does not work

Question

I've seen tons of posts about this, but the DELETE method of my new WebAPI simply does not work and returns a 404, using Windows 7 32-bit, IIS 7.5.

I've tried

• Uninstalling WebDAV
• Adding PUT, DELETE, OPTIONS to the ExtensionlessUrlHandler-Integrated-4.0 handler (and 32bit/64bit handlers).
• Allowing all modules to run.

All to no avail and all return 404. If I change the DELETE type to a GET, then the service runs the GET command perfectly fine.

Anyone with any other ideas about this? It's driving me crazy.

EDIT:

I'm calling the DELETE method like this (mediator is a wrapper around the jQuery call):

mediator.publish("AjaxCall", {
                url: "/api/files/" + $(a.currentTarget).data("fileid"),
                type: "DELETE",
                }
            });

And WebAPI:

// DELETE api/<controller>/5
// [HttpDelete] - Tried this too
public void Delete(int fileId)
{
     Files.DeleteFile(fileId);
}

And relevant web.config:

<handlers>
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <modules runAllManagedModulesForAllRequests="true">
      <remove name="WebDAVModule" />
    </modules>

Answer 1

The Solution is to add PUT & DELETE verb in correct applicationHost.config file.

For IIS :

Go to lcation: C:\Windows\System32\inetsrv\config and edit the applicationHost.config file as:

 <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
  <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
  <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />  

For IIS EXPRESS GO TO : %userprofile%\documents\iisexpress\config\ and do the same in applicationHost.config file.

Answer 2

Are you hosting under "Default Web Site" ? If yes then try hosting it separately on a different port.

I have the same issue with PUT and DELETE and the workaround was successful.

Answer 3

If You are using attribute routing, update AcceptVerbs with DELETE and PUT methods like this :

[Route("{fileId:int}")]
[AcceptVerbs("DELETE")]
public void Delete(int fileId)
{
   Files.DeleteFile(fileId);
}

Also if you are writing fileId as parameter name then dont forget to update the webAPI route config to api/files/{fileId}

And also use AcceptVerbs attribute for GET and PUT as well because these three have same URL structure to call their methods. Also update the Controller with RoutePrefix as below:

[RoutePrefix("api/files")]
public class FileController : ApiController
{
}