swagger1.cs

 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
      if (env.IsDevelopment())
      {
          app.UseDeveloperExceptionPage();
          app.UseSwagger();
          app.UseSwaggerUI(c =>
          {
              c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyWebAPI Helper Page");
          });
      }
      else
      {
          app.UseExceptionHandler("/Home/Error");
      }

      app.UseStaticFiles();
}