As I can perform a mediating search a date range with two datetimepicker and a button it is worth noting that I filled my datagridview in this way:
adapter = new MySqlDataAdapter("Mostrar_ClientesExamen", C.conect);
adapter.SelectCommand.CommandType = CommandType.StoredProcedure;
table = new DataTable();
adapter.Fill(table);
gridControl1.DataSource = table;
C.CerrarConexion();