private void listar() { try { this.roles = new Roles(); this.roles.opc = 1; this.rolH = new RolesHelper(roles); this.table = new DataTable(); this.table = rolH.ListarRol(); if (table.Rows.Count > 0) { this.dgvListar.DataSource = table; } } catch (Exception ex) { MessageBox.Show(ex.Message); } }