how to create custom data annotation for display name MVC

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Web;
using TM_3_1_16.Models;



namespace TM_3_1_16
{

    public class getfieldsdisplayname : DisplayNameAttribute
    {

        public getfieldsdisplayname(string tblname, string colname)
            : base(GetMessageFromResource(tblname, colname))
        {
        }

 

        private static string GetMessageFromResource(string tblname, string colname)
        {
            DBContext db = new DBContext();

            // colname = base.displayname // I want to retrun which is current porpery name, so that I can find display name in database based on the current field name retrun display name from Database 

            return db.fieldsnames.Where(col => col.ColumnsName == colname).Select(dis => dis.DisplayName).FirstOrDefault().ToString();
        }

    }
  
}