private void button1_Click(object sender, EventArgs e)
{
    using (MySqlConnection con = new MySqlConnection("server=xxxx;user=xxxx;database=xxxx;password=xxxx;"))
    {
        try
        {
            con.Open();
            MessageBox.Show("Подключился");
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }
}