private void btnNew_Click(object sender, EventArgs e)
        {
            AgendaCadastro frmAgenda = new AgendaCadastro();

            frmAgenda.ShowDialog();

            AtualizaForm();
        }
        private void grdAgenda_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex > -1 && e.ColumnIndex > -1)
            {
                var _agenda = (Agenda)grdAgenda.Rows[e.RowIndex].DataBoundItem;

                AgendaCadastro frmAgenda = new AgendaCadastro(_agenda);
                frmAgenda.ShowDialog();
            }
        }