public void preencheGrid()
{
objmateria.idusuario = int.Parse(Session["idusuario"].ToString());
MateriasGridView.DataSource = objmateria.BuscarMateria();
MateriasGridView.DataBind();
}
private void CarregaDropDownList()
{
ddMaterias.DataSource = objmateria.BuscarMateria();
ddMaterias.DataValueField = "idmateria";
ddMaterias.DataTextField = "Nome";
ddMaterias.DataBind();
ddMaterias.Items.Add(new ListItem("Selecione:", "0"));
ddMaterias.SelectedValue = "0";
}