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vb.netsortingobjectlistview

Turning Off Grouping In ObjectListView Turns Of Sorting

I am struggling to find information on a lot of small issues I'm starting to come across since recently integrating the ObjectListView into my application. I must admit, I love the control and it takes a lot of work away from me by having the control pretty much do everything that I need.

However, amongst a few issues that I've come across thus far, one is the fact that if I turn off grouping for individual columns it no longer allows me to sort these columns.

For example, my ListView control has an ID, Summary, Location, etc., etc. I currently run grouping on the ID because I attach a unique footer against every ID and it looks good. But, when I click on Summary, or Location it then groups all items by Summary or Location and therefore I end up with the group header but no footer anymore because the footer no longer corresponds with the ID.

What I want to achieve is to allow the user to click on any other column, but still maintain the group by ID and thus keep the footer against each item. I only want the items to sort, not group, but as mentioned, when I turn off the grouping against each column, it turns off the sort function.

UPDATE

Basically, looking at the screenshot below, I want to be able to click on the Priority Column Header (for example) to sort the list of object by Priority, but still maintain the Group By Ticket (with the Group Footer details). And basically be able to click on any Column header to sort the list but keeping the grouping by Ticket.

enter image description here

I have intercepted the OLV_BeforeCreatingGroups event to add:

e.Parameters.GroupByColumn = Ticket_ID

This now seems to maintain my grouping by Ticket no matter what Column header I click on, but I now loose the sort functionality.

Solution

  • Try setting AlwaysGroupByColumn to be the TicketId column. That will do the trick :)

    Second attempt:

    Thanks for the screenshot. I think I understand what you want. You are hoping that clicking on the header will sort the groups themselves. That's not the default behaviour, which is to sort the rows within each group.

    To do what you are asking:

    1. Listen for BeforeCreatingGroups event and fill in the GroupComparer property on the event argument block. This comparer controls the ordering of the groups.

    2. The default group order is based on OLVGroup.SortValue. So you could install a GroupFormatter delegate and change the SortValue for each group so they are ordered in the manner you want.

    In either case, you will need to use PrimarySort and PrimarySortOrder to know which column the user last clicked.