protected void cmdBuscar_Click(object sender, EventArgs e)
        {
            try
            {
                AlunoDTO dto = new AlunoDTO();

                if (txtAno.Text.Length > 0)
                {
                    dto.ano = int.Parse(txtAno.Text);
                }

                dto.situacao = cmbSituacao.SelectedValue.ToString();

                AlunoBRL brl = new AlunoBRL();
                grdAluno.DataSource = brl.searchAlunosCompraDevices(dto);
                grdAluno.DataBind();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }