Not supported by Swagger 2.0: Multiple operations with path

问题

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?

回答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(){....}

回答2:

You have two options for the above two methods:

1. Combine two methods into single one with three parameters - each one will be in the query string

2. Have separate route urls like - api/controller/byusername and api/controller/bycredentials

回答3:

You can change the route on your controller.

The default value is [Route("api/[controller]")]

You can change to [Route("api/[controller]/[action]")]

回答4:

The problem can also occur in a situation where you use attribute routing.

If the attribute route conflicts with a routingtable route you will have the 'multiple operations' error.

Example:

[HttpGet]
[SwaggerOperation("GetByUsername")]
[Route("[path]/User")]
public IHttpActionResult GetUser(string username)
{

}

more info on attribute routing: https://docs.microsoft.com/en-us/aspnet/web-api/overview/web-api-routing-and-actions/attribute-routing-in-web-api-2

回答5:

Add seperate route on your conflicting methods. Such as [Route("GetByType")] above of one and [Route("GetById")] on another

回答6:

An answer I haven't seen: I bungled up usings.

My controller has some MVC items (List items) and thus has a link:

using System.Web.Http;
using System.Web.Mvc;

Because of this, somehow, it got registered twice (I assume). Problem was fixed by using the full qualification for RoutePrefix/Route/HttpGet and others.

namespace MyNameSpace
{
    [System.Web.Http.RoutePrefix("api/Reports")]
    public class ReportsController
    {
        {...constructor...}

        [System.Web.Http.Route("Scans")]
        [System.Web.Http.HttpGet,ResponseType(typeof(List<ReportClass>))]
        public ascyn Task<HttpResponseMessage> GetScans() {...}

回答7:

Add route attribute for the method [Route("ApiAnotherFunction")] and [HttpGet].

来源：https://stackoverflow.com/questions/39601890/not-supported-by-swagger-2-0-multiple-operations-with-path