Issue with sqlexpress connection in windows forms application

 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Trpg
{
   
    public partial class TRPG : Form
    {
        //inserting class for sql connect here
         public class Connect
            {
        SqlConnection tconnect;

        public object TRPGConnect()
        {
            tconnect = new SqlConnection(@"server = .\sqlexpress;integrated security = true                ;database = trpg");
            return tconnect;
        }
            }
        //end of sql connect class here


        // create an instance of the connection.
        Connect trpgc = new Connect();
        
        

        public TRPG()
        {
            InitializeComponent();
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void TRPG_Load(object sender, EventArgs e)
        {
            

        }
        
        public void testConnect()
        {
            tconnect.Open();
            tconnect.Close();
        }
}
}