How to get Json format data in WebApi

Question

I want to get Json Data from WebApi when i call apiController it can return Xml data.

 

here is ShowDataController = ApiController

             Sp_GetAllData() = Storeprocedure which contains simple select query 

 

public class ShowDataController : ApiController

{

            public IEnumerable<Sp_GetAllData_Result> Get()

            {

                     AngulerEntities db = new AngulerEntities();

                     List<Sp_GetAllData_Result> res = db.Sp_GetAllData().ToList();

                     return res;

            } 

}

 

when i run this  http://localhost:10127/api/ShowData it will return xml data 

if i use string type of method in ApiController and which is using JavaScriptSerializer().Serialize()

 

string output = new JavaScriptSerializer().Serialize(res);

return output;

 it will return xml in json data.

now i want to get Only json data while calling apiController.