Conectando no SQL SERVER com C#

Classe para Abrir e Fechar conexão com Sql erver.

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

namespace br.conexao
{
public class Conexao
{
private String connectionString;

private SqlConnection connection;

public void open()
{
  connectionString = "ADICIONE AQUI SUA CONNECTION STRING";
  connection = new SqlConnection(this.connectionString);
  this.connection.Open();
}

public void close()
{
  if (this.connection.Equals(null) == false)
  {
    if (this.connection.State == ConnectionState.Open)
    {
      this.connection.Close();
    }
  }
}
}
}