public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        void InitJsonSettings(JsonSerializerSettings serializerSettings)
        {
            // Use DefaultContractResolver or CamelCasePropertyNamesContractResolver;
            serializerSettings.ContractResolver = new DefaultContractResolver();

            // Configure JsonSerializer to properly serialize NodaTime types.
            serializerSettings.ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);
        }

        // CASE1: AddMvcCore with AddJsonFormatters
        services
            .AddMvcCore()
            .AddApiExplorer()
            .AddJsonFormatters(InitJsonSettings)
            ;

        // CASE2: AddMvc with AddJsonOptions
        //services
        //    .AddMvc()
        //    .AddJsonOptions(options => InitJsonSettings(options.SerializerSettings))
        //    ;

        // Adds swagger
        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new Info { Title = "My API", Version = "v1" });

            // Configures swagger to use NodaTime.
            // c.ConfigureForNodaTime();

            // Configures swagger to use NodaTime. Use the same InitJsonSettings action that in AddJsonFormatters
            c.ConfigureForNodaTime(InitJsonSettings);

            // Configures swagger to use NodaTime with serializerSettings.
            // c.ConfigureForNodaTime(serializerSettings);
        });
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMvc().UseSwagger();

        // Adds swagger UI
        app.UseSwaggerUI(c =>
        {
            c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
        });
    }
}