Query sort field autoSum

[ist]

Hi,
How can I set AutoSum property on sorting field into Query with x++




I do this into Query Init method but without success.

    this.query().dataSourceTable(tablenum(LedgerTrans)).sortClear();
    this.query().dataSourceTable(tablenum(LedgerTrans)).addSortField(fieldnum(LedgerTrans, Voucher), SortOrder::Ascending);
    this.query().dataSourceTable(tablenum(LedgerTrans)).addSortField(fieldnum(LedgerTrans, TransDate), SortOrder::Ascending);
    this.query().dataSourceTable(tablenum(LedgerTrans)).addSortField(fieldnum(LedgerTrans, AccountNum), SortOrder::Ascending);
    this.query().dataSourceTable(tablenum(LedgerTrans)).autoSum(fieldNum(LedgerTrans, Voucher));

thank's in advance