How To Create ASP.NET Web API

This blog will demonstrates steps by steps web API tutorial that explain what is WEB API and how to create a new ASP.NET Web API in ASP.NET MVC and explain its characteristics. for more information please read my blog The Lifecycle of an ASP.NET Web API where we discussed about the life cycle of an ASP.NET Web API message, how it travels from Server to client.

What is Web API?

ASP.NET Web API is a very light weight .net framework to create HTTP service and it is very easy to build restful service, which covers boarder client like mobile device, desktop and other platform.

Characteristic of Web API:

·         ASP.NET Web API creates Web API on top of ASP.NET and so it can use ASP.NET request/response pipeline.

·         ASP.NET Web API maps with HTTP verbs (GET, POST, PUT etc.) to Method Name.

·         It supports many response Data formatter (like JSON, XML, BSON).

·         It supports only HTTP protocol.

Here is 4 simple steps to create ASP.NET WEB API by using visual studio.

 Step 1: Create an ASP.NET Web Application in Visual Studio:

   Open visual studio and open new project.

   Select Visual C# a Web Asp.NET Web Application (.Net Framework) Template 

Select Empty project template - it’s an empty project template for creating ASP.NET Web API project

  Here is Web API Empty Project - SimpleWebAPI

Step 2: Add Web API Controller 

Select and right click Controllers >>Add >> Controller

Select Web API 2 Controller – Empty - to create an empty Web API controller

Provides API Controller Name – TaskController.cs

Here is TaskController Controller Generated Class, which is by default inherited by ApiController abstract class, which provides many importance properties and methods related to WEB API

C# : TaskController.cs

     public class TaskController : ApiController

      {

        public TaskController()

        {

        }  

      }

Step 3: Add Model Class –Task.cs

     Here is Model Class - Task, which is used to transfer data from /to Web API

C# : Task.cs

    public class Task

       {

        public int TaskID { get; set; }

        public string Description { get; set; }

       }

    

   Step 4: Add API Controller Method

   Add GetTaskByID API Controller method to return the Task Model object based on input taskID

   C# Code: TaskController.cs

    public class TaskController : ApiController

    {

        public TaskController()

        {

        } 

      

        [HttpGet]

        public Task GetTaskByID(int taskID)

        {

            //@Todo Logic to get task by ID

            return new Task() {  TaskID = 1001, Description = "Todo Task"};

        }

    } 

    By default WebApiConfig.cs class contain WEB API routing settings

    C#: WebApiConfig.cs

      public static class WebApiConfig

    {

        public static void Register(HttpConfiguration config)

        {

            // Web API configuration and services

            // Web API routes

            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(

                name: "DefaultApi",

                routeTemplate: "api/{controller}/{id}",

                defaults: new { id = RouteParameter.Optional }

            );

        }

    }

  

It’s done!! Your web API is ready for use.

 Now build Web API project and Run the below URL

URL:  http://localhost:27510/api/task?taskid=1

You can use google postman tool to test web api 

 HTTP Get: http://localhost:46816/api/task?taskid=1

     For API more interactive documentation you can use the Swagger UI and easily setup swagger for ASP.NET Web API

Other related Posts:

ASP.NET Web API Caching

Steps To Improve ASP.NET Web API Performance

4 Simple Steps To Create ASP.NET Web API

Parameter Binding or Model Binding in ASP.NET Web API

The Life-cycle of an ASP.NET Web API