Understanding Self-Hosting of a Web API (C#): Part 1

Introduction

This article provides a walkthrough of self-hosting a Web API. Here we will see how to host a web API inside a console application.

Step 1: To create a new project, open Visual Studio 2013 in Admin mode then click on "File" -> "New" -> "Project..." then select "Console Application".

Step 2: Install "Microsoft.AspNet.WebApi.SelfHost" through the Packager Manager console as shown below. Click on "Tools" then select "Library Package Manager" --> "Package Manager Console" and type the following command:

Install-Package Microsoft.AspNet.WebApi.SelfHost

Step 3: Create a Model and Controller and add the following implementation as shown below: 

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
namespace SelfHost1  
{
    public class book
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Author { get; set; }
        public decimal Rating { get; set; }
    }
}

Now add a public class named BooksController. Derive this class from "System.Web.Http.ApiController".

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Web.Http;
namespace SelfHost1
{
    public class BooksController
    {
        book[] books = new book[]
        {
            new book { Id = 1, Name = "Sagar", Author = "seventh", Rating = 5 },
            new book { Id = 2, Name = "Sachin", Author = "seventh", Rating = 4 },
            new book { Id = 3, Name = "Dravid", Author = "seventh", Rating = 3 },
            new book { Id = 4, Name = "Ramesh", Author = "seventh", Rating = 2 },
            new book { Id = 5, Name = "Ganguly", Author = "seventh", Rating = 1 },
            new book { Id = 6, Name = "Rahul", Author = "seventh", Rating = 6 },   
        };
        public IEnumerable<book> GetAllBooks()
        {
            return books;
        }
        public book GetBookById(int id)
        {
            var book = books.FirstOrDefault((p) => p.Id == id);
            if (book == null)
            {
                throw new HttpResponseException(HttpStatusCode.NotFound);
            }  
            return book;
        }  
        public IEnumerable<book> GetBooksByStandard(string author)  
        {
            return books.Where(p => string.Equals(p.Author, author,
                    StringComparison.OrdinalIgnoreCase));  
        }
    }
} 

Let's host a Web API.

Open the Program class file from the Solution Explorer.

using System;
using System.Web.Http;
using System.Web.Http.SelfHost;
namespace SelfHost1
{
    class Program
    {
        static void Main(string[] args)
        {
            var config = new HttpSelfHostConfiguration("http://localhost:8080");
            //To determine which action to invoke, the framework uses a routing table. The Visual Studio project template for Web API creates a default route
            config.Routes.MapHttpRoute(
                "API Default", "api/{controller}/{id}",
                new { id = RouteParameter.Optional });  
            using (HttpSelfHostServer server = new HttpSelfHostServer(config))  
            {
                server.OpenAsync().Wait();
                Console.WriteLine("Listening for HTTP requests.");
                Console.WriteLine("(Please Run the ClientApp project to send requests).");
                Console.WriteLine();
                Console.WriteLine("You can hit Enter to quit.");
                Console.ReadLine();
            }
        }
    }
}

Run the application; the following window should appear:

Summary

In this article, I explained how to self-host a Web API. In the next part we will see how to call a Web API from a client application.

Next Article: Understanding How to Call the Web API From a Client Application (C#): Part 2