Return connection from Abstract class using C#

Hi,

I need connection to establish from abstract class to other class in forms.

How to do it. My code below. 

using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

public abstract class AbstractClass1
{
    // Abstract method (does not have a body)
    public abstract void DBConnection(); 
}

// Derived class (inherit from AbstractClass1)
 class Connection : AbstractClass1
{
    public override void  DBConnection()
         //public override string ToString(string con)
    {
        // The body of  DBConnection is provided here
        SqlConnection con = new SqlConnection("Data Source = xxxxxx; Initial Catalog = Test; User ID = sa,;Password=xxxxx");
    }
}

//other form 
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.Threading.Tasks;
using System.Windows.Forms;
using AbstractClass;

namespace AbstractClass
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnView_Click(object sender, EventArgs e)
        {           
            Connection con = new Connection();
            con.DBConnection(); // how to get connection here from abstract class 
           
            SqlCommand cmd = new SqlCommand("Select * from Emp");
           // cmd.Connection = con;
            DataTable dt = new DataTable();
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(dt);
            if(dt.Rows.Count>0)
            {
                dataGridView1.DataSource = dt;
            }            
        }