Swagger UI shows empty page - How to fix?

Stranded here after unsuccessfully publishing this issue at StackOverflow and swagger-api/swagger-ui:

I added Swashbuckle.AspNet.Core to my repository and initialized everything using defaults.

Although I can see JSON output from /swagger/v1/swagger.json opening /swagger/index.html just yields an empty page.

Why?

Here’s my code

public void ConfigureServices(IServiceCollection services)
{
  services
    .AddSwaggerGen()
    .AddControllers()
    ;
}

// This method gets called by the runtime once. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env, Options options)
{
  if (env.IsDevelopment()) app.UseDeveloperExceptionPage();

  app
    .UseHttpsRedirection()
    .UseRouting()
    .UseAuthorization()
    .UseEndpoints(endpoints => endpoints.MapControllers())
    .UseSwagger()
    ;

  if (env.IsDevelopment()) app.UseSwaggerUI();
}

Issue Analytics

State:
Created 3 years ago
Comments:8

Top GitHub Comments

5reactions

shawtycommented, Jul 30, 2020

Update 2:

It appears that the “c.SwaggerEndpoint” call is NOT OPTIONAL and MUST BE SPECIFIED

None of the documentation I’ve read tells the user this, and so it’s quite feasible that like myself and @SetTrend that we would leave this out.

As for the reason I had that call commented out in my screen shots above, I was actually trying to solve A 404 error with “/swagger” not being found when I landed here.

I’ve since figured out that the cause of my problem was bogus advice from the MS-Docs site which suggests setting “c.RoutePrefix” to String.Empty.

@SetTrend for now you can resolve your problem, simply by specifying your “c.SwaggerEndpoint” call in the same manner I do in the above image. This add’s a single swagger JSON document object to the UI for you to use.

2reactions

shawtycommented, Jul 31, 2020

@SetTrend I’ve not looked deep enough into the code to be honest, it only bit me because I was trying to solve a micro-services rest boundary problem on one of my clients projects 😃 but I guess it wouldn’t be a huge ache, my best guess without looking at the code would be to copy the default generated URL into the config object in .NET at some appropriate point.

PS: I’ve answered your Stack Overflow post too 😃