Not supported by Swagger 2.0: Multiple operations with path

Question

I have integrated swagger in WebApi 2 application. It works fine when application has single controller. When I added second controller in the application. I got following error :

An error has occurred.","ExceptionMessage":"Not supported by Swagger 2.0: Multiple operations with path 'api/Credential' and method 'GET'. See the config setting - \"ResolveConflictingActions\" for a potential workaround","ExceptionType":"System.NotSupportedException","StackTrace":" at Swashbuckle.Swagger.SwaggerGeneratorOptions.DefaultConflictingActionsResolver(IEnumerable1 apiDescriptions)\r\n at Swashbuckle.Swagger.SwaggerGenerator.CreatePathItem(IEnumerable1 apiDescriptions, SchemaRegistry schemaRegistry)\r\n at Swashbuckle.Swagger.SwaggerGenerator.<>c__DisplayClass7.b__4(IGrouping2 group)\r\n at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable1 source, Func2 keySelector, Func2 elementSelector, IEqualityComparer1 comparer)\r\n at Swashbuckle.Swagger.SwaggerGenerator.GetSwagger(String rootUrl, String apiVersion)\r\n at Swashbuckle.Application.SwaggerDocsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Net.Http.HttpMessageInvoker.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Web.Http.Dispatcher.HttpRoutingDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Net.Http.DelegatingHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n at System.Web.Http.Cors.CorsMessageHandler.<SendAsync>d__0.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.HttpServer.d__0.MoveNext()"} http://localhost:50950/swagger/docs/v1

In the second controller I have added following two methods.

 string Get(string username, string password);

 string Get(string credential);

If I comment one of the method. Then it works fine.

Any Idea how to fix it?

Answer 1

In the file AppStart/SwaggerConfig.cs

First one, you must import Linq

using System.Linq;

And add in the same file, this line

c.ResolveConflictingActions(apiDescriptions => apiDescriptions.First());

just inside of:

GlobalConfiguration.Configuration 
                .EnableSwagger(c =>
                    { ...

One consideration: In your controllers, you must use the Http methods :

[HttpGet]
[Route("something")]
public List<model> something(){....}

[HttpGet]
[Route("something2")]
public List<model2> something2(){....}

[HttpPost]
[Route("mypost1")]
public List<model> mypost1(){....}

[HttpPost]
[Route("mypost2")]
public List<model2> mypost2(){....}