LevelcodeLicenseAPP/DataAccess/DbConexao.cs

using System;
using System.Configuration;
using System.Data.SqlClient;

namespace LevelCode.License.DataAccess
{
    public class DbConexao : IDisposable
    {
        private readonly SqlConnection _conexao;

        public SqlConnection Conexao
        {
            get { return _conexao; }
        }

        public DbConexao()
        {
            string connectionString = ConfigurationManager
                .ConnectionStrings["SQL"].ConnectionString;

            _conexao = new SqlConnection(connectionString);
        }

        public void Abrir()
        {
            if (_conexao.State != System.Data.ConnectionState.Open)
                _conexao.Open();
        }

        public void Fechar()
        {
            if (_conexao.State != System.Data.ConnectionState.Closed)
                _conexao.Close();
        }

        public void Dispose()
        {
            if (_conexao != null)
            {
                Fechar();
                _conexao.Dispose();
            }
        }
    }
}