Thanks for the reply.

I am also doing some tweaks, but it's good to have the grid functioning properly.

I found out that when the grid is empty and when you assign the datasource, the groupings are faster. If you already have data then second time onwards the grid loads slow. So, I created a delegate and before invoking the delegate, I am emptying the grid and on callback function, I am reassigning the datasource. This refreshes the grid much faster.

 Also, I minimized the calculations while grouping, by precalculating some columns. Another thing I am doing is loading the child bands while expanding the parent row.

Better luck!

Hello,

My team and me have the same problem with UltraGrid : when the DataSource already contains a list of object and we perfrom outlook group by, it's very quick. But when the DataSource is empty, a outlook group by is already performed and we assign a list to the DataSource it's very very slow.

We have upgraded to the latest Infragistics WinForm 2007 Vol 3 + HotFix, but the problem persist.

Infragistics : is this bug already identified ? Is there a hotfix in preparation for that ?

Thank you (and sorry for my bad English).

I submitted this two months ago and received the following reply. Since then, nothing.

I was able to reproduce the behavior of long calculation time of the summary formula at my end. I have logged this behavior with our developers in our tracking system, with an issue ID of BR30242. This development issue will be assigned to a developer to research for a fix, workaround, or other resolution. If some other resolution is reached, I will contact you with this information.

Issue Description: "Long calculation time for the SummaryFormula in the UltraWinGrid in GroupBy mode".

Then I recommend contacting Infragistics Developer Support and following up with them on the status of the issue.  

Infragistics sent me a workaround:

1. Install the latest hot fix (2007 V3 or 2008 v1).

2. In the BeforeSortChange event, add the following: e.ProcessMode = ProcessMode.Synchronous;

This fixed the test app that I sent them, but our production App still would hang up calculating summaries when re-sorting. I found an additional workaround which, in combination with the above, eliminated this behavior:

 3. In the BeforeSortChange event, remove the summarycolumns that are of type SummaryType.Formula, using code like the following:

Light at the end of the tunnel ....?

 I think this bug is not connected with custom formulas.

For me the necessary conditions for reproducing are:
There are many rows in grid (> 1000) and 3 or more columns are "grouped by".
If I clear the data source and fill it with the new data, the application hangs.

Here is a workaround I use:

I've created the following class:

public class SwitchOffGroupByCookie : IDisposable
{
    private readonly UltraGrid grid_;
    private readonly UltraGridLayout layout_ = new UltraGridLayout();

    public SwitchOffGroupByCookie(UltraGrid grid)
    {
        grid_ = grid;
        layout_.CopyFrom(grid_.DisplayLayout);
        grid_.DisplayLayout.Bands[0].SortedColumns.Clear();
    }

    public void Dispose()
    {
        if (layout_.Bands[0].SortedColumns.Count > 0)
        {
            foreach (UltraGridColumn col in layout_.Bands[0].SortedColumns)
            {
                grid_.DisplayLayout.Bands[0].SortedColumns.Add(col.Key,
                                                               (col.SortIndicator == SortIndicator.Descending),
                                                               col.IsGroupByColumn);
            }
        }
    }
}

using (new SwitchOffGroupByCookie(grid_)) 
{
    dataSource_.Rows.Clear();
    // fill data source with the new data
}