Hello Craig,
You need to attach to NTreeList.ColumnNotify event and in the event handler to do the following:
void nTreeList1_ColumnNotify(object sender, NTreeListColumnNotifyData data)
{
if (data.NotifyCode == NTreeList.ColumnSortingNotifyCode)
{
data.Cancel = true;
}
}
If you need this only for certain column(s) you need to check the column along with the notify code:
if (data.NotifyCode == NTreeList.ColumnSortingNotifyCode && data.Column == col) ...
Best Regards,
Nevron Support Team