private void EventtxtDataEmissao_Click(object sender, EventArgs e)
        {
            DatePickerHelper frag = DatePickerHelper.NewInstance(delegate(DateTime time)
            {
                txtDataEmissao.Text = time.ToString("dd/MM/yyyy", CultureInfo.GetCultureInfo("pt-BR"));
            });

            frag.Show(FragmentManager, DatePickerHelper.TAG);
        }
        private void TxtDataEntrega_Click(object sender, EventArgs e)
        {
            DatePickerHelper frag = DatePickerHelper.NewInstance(delegate(DateTime time)
            {
                //var teste = DateTime.Now.ToString("hh:mm:ss");
                txtDataEntrega.Text = time.ToString("dd/MM/yyyy", CultureInfo.GetCultureInfo("pt-BR"));
            });

            frag.Show(FragmentManager, DatePickerHelper.TAG);
        }