ASP.NET Web API : Return data in JSON format

In this article I am going to explain how to return data in JSON format from ASP.NET Web API.

In previous article I have explained how to create First WebAPI Hello World application with repository pattern, how to create Web APIfirst Hello world application and Introduction To ASP.NET Web API.

As you know ASP.NET Web API by default return the data in XML format when we run the API in browsers. Here, we are going to learn to change the return data/response to JSON.

You can achieve this from WebApiConfig.cs file. You can find this file under App_Start folder. Firstly, add the namespace to config file

using System.Net.Http.Headers;

 and add the below given code in this file:

 config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));

Complete code of WebApiConfig.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net.Http.Formatting;

using System.Net.Http.Headers;

using System.Web.Http;

using Unity;

using WEBAPI.Models;

using WEBAPI.Interface;

using WEBAPI.Services;

namespace WEBAPI

{

    public static class WebApiConfig

    {

        public static void Register(HttpConfiguration config)

        {

            // Web API reutrn Json data       

            config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));

             // Web API routes

            config.Routes.MapHttpRoute(

                name: "DefaultApi",

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

                defaults: new { id = RouteParameter.Optional }

            );

        }

    }

}

If you want return data in both XML and JSON format, then you need to pass querystring parameter.

Complete code of WebApiConfig.cs to return data in both JSON &XML

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net.Http.Formatting;

using System.Net.Http.Headers;

using System.Web.Http;

using Unity;

using WEBAPI.Models;

using WEBAPI.Interface;

using WEBAPI.Services;

namespace WEBAPI

{

    public static class WebApiConfig

    {

        public static void Register(HttpConfiguration config)

        {

            // Web API reutrn both Json & XML data                    GlobalConfiguration.Configuration.Formatters.JsonFormatter.MediaTypeMappings.Add(new QueryStringMapping("format", "json", new MediaTypeHeaderValue("application/json")));

            GlobalConfiguration.Configuration.Formatters.XmlFormatter.MediaTypeMappings.Add(new QueryStringMapping("format", "xml", new MediaTypeHeaderValue("application/xml")));

            // Web API routes

            config.Routes.MapHttpRoute(

                name: "DefaultApi",

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

                defaults: new { id = RouteParameter.Optional }

            );

        }

    }

}