add swagger to web api .net core 3.1 code example

Example 1: integrate swagger in .net core api

/*
To use swagger in an existing .net core api ALL functions must be annotated.
examples of annotations:
[HttpGet], [HttpPost], [NonAction] (for non HTTP actions)
*/ 


// in View>Other Windows>Package Manager Console add package:
Install-Package Swashbuckle.AspNetCore

// in startup.cs add:
using Microsoft.OpenApi.Models;

// in startup.cs edit functions:
// ConfigureServices():
            services.AddMvc();
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo { Title = "<title>", Version = "v1" });
            });

// Configure():
            app.UseSwagger();
            app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "<title> v1"));

// in launchSettings.json add to all profiles:
      "launchUrl": "swagger"

Example 2: swaggergen add service not getting info in .net core

services.AddSwaggerGen(c =>
{
    c.SwaggerDoc("v1", new OpenApiInfo { Title = "The API", Version = "v1" });
});

Example 3: swaggergen add service not getting info in .net core

using Microsoft.OpenApi.Models;