swagger.json paths and definitions are empty. No operations defined in spec

after some research i was found that my problem was about using swagger along with OData in .NetCore2.1. i found a solution for this problem.

first i added two following Nuget packages:

Swashbuckle.AspNetCore
Swashbuckle.AspNetCore.Annotations

then, i added following codes in Startup.cs

services.AddMvc(options => {
                foreach (var outputFormatter in 
options.OutputFormatters.OfType<ODataOutputFormatter>().Where(_ => 
_.SupportedMediaTypes.Count == 0))
                {
                    outputFormatter.SupportedMediaTypes.Add(new 
MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
                }
                foreach (var inputFormatter in 
options.InputFormatters.OfType<ODataInputFormatter>().Where(_ => 
_.SupportedMediaTypes.Count == 0))
                {
                    inputFormatter.SupportedMediaTypes.Add(new 
MediaTypeHeaderValue("application/prs.odatatestxx-odata"));
                }
            }).SetCompatibilityVersion(CompatibilityVersion.Version_2_1);

the, i added following code line in controllers:

[ApiExplorerSettings(IgnoreApi = false)] 

please note that it was worked for me but it may be need more research for eventually side effects

Sounds like you need to add some routes in the controller. With rest services you will need to add them separate from what was built automatically by Visual Studio. for example // GET: Items [HttpGet] [Route("/items")] ...rest of function... this will give your swagger a reference to what it does when you click the button.

you need to enable XML Documentation file under project obtions => Build tab.

Then you need to read this file through swagger so that swagger can create documentation from it.

private static string[] XmlCommentsFilePath
{
    get
    {
        var basePath = PlatformServices.Default.Application.ApplicationBasePath;

        var apiDocFile = typeof(Startup).GetTypeInfo().Assembly.GetName().Name + ".xml";
        var apiPath = Path.Combine(basePath, apiDocFile);

        return new[] {apiPath};

    }
}

In ConfigureServices

services.AddSwaggerGen(options =>
{ 
    var provider = services.BuildServiceProvider().GetRequiredService<IApiVersionDescriptionProvider>();

    // add a swagger document for each discovered API version
    provider.ApiVersionDescriptions.ForEach(x => options.SwaggerDoc(x.GroupName, CreateInfoForApiVersion(x)));

    ....
});

Please add a in contoller any method like a then showing swagger methods

  [HttpGet]
    [EnableQuery]
    public IQueryable<int> Get()
    {
        return 1;
    }