Hi,

I can't be sure, there might be some obscure reason for this, but at first glance, this looks like a bug to me. The grid's UIElement is getting dirtied and it's verifying the sorted order of the rows, but since the sort operation was canceled, I can't see any reason for the grid to be doing that. Looks like it's an oversight. It's not terribly harmful, which is probably why no one noticed it, but I can see how it might be detrimental to performance in some cases.

So I'm going to forward this thread over to Infragistics Developer Support and have them write this up for developer review.

Thanks for looking into this Mike.

In the meantime, is there any sort of workaround for this.  Here's why it's especially detrimental for us.

Some time ago, our product management decided they wanted double-click, instead of single click, on a column header initiate a sort.  To do this we jump through some hoops to cancel the sort event on the first click, but allow it on the second.

Because the cancel for the BeforeSort event isn't stopping the processing of the sort logic, when a user double clicks on a column in our app, it's essentially performing two sorts (but only displaying the results once).

When the dataset is small this isn't much of an issue.  But as the number of rows grows, this becomes a very obvious performance hit.

Unless you have a suggestion, I'm probably going to suggest to management that we go back to single click sorting.

Chris Rowland

Hi Chris,

A column has to be sorted in order to be grouped, so I guess in most cases, it would not make sense for the HeaderClickAction to apply to the GroupByButton.

Are you allowing the users to do the grouping or are you doing it in code?

What you can probably do is use a flag that determines whether each change to sorting is allowed. Then you check that flag inside the BeforeSortChange event. Then any time you want to change the sorting in code, you set the flag first, then set the Sortindicator, then set the flag back.

Something like this:

        private void ultraGrid1_DoubleClickHeader(object sender, DoubleClickHeaderEventArgs e)
        {            
            switch (e.Header.Column.SortIndicator)
            {
                case SortIndicator.Ascending:
                    this.SetSortIndicator(e.Header.Column, SortIndicator.Descending);
                    break;
                case SortIndicator.None:
                case SortIndicator.Descending:
                    this.SetSortIndicator(e.Header.Column, SortIndicator.Ascending);
                    break;
                case SortIndicator.Disabled:
                    break;
            }            
        }

        private void SetSortIndicator(UltraGridColumn column, SortIndicator sortIndicator)
        {
            this.allowSortChange = true;
            try
            {
                column.SortIndicator = sortIndicator;
            }
            finally
            {
                this.allowSortChange = false;
            }
        }

        bool allowSortChange = false;
        private void ultraGrid1_BeforeSortChange(object sender, BeforeSortChangeEventArgs e)
        {            
            if (false == this.allowSortChange)
                e.Cancel = true;
        }

If you need to group a column, you do the same thing with the flag, since grouping a column will fire BeforeSortChange. If you need the users to be able to group the columns, then it becomes a bit more complicated as you will have to put a check in BeforeSortChange to see if the groupings are changing and allow that.

Thanks Mike.  That gets me *really close* to what I'm looking for.  Single click on the column header is no longer triggering a BeforeSort event, and only fires once on double click.

The only unwanted behavior I'm seeing now is that this doesn't seem to apply to GroupByColumnHeaders when the grid is in ShowGroupBy mode and such a column exists.  Single click on the group by column is still performing a sort.

I would think the HeaderClickAction would apply to all column headers but maybe that's not the case?

Thanks

Chris Rowland

Hi Chris,

How about turning off the grid's automatic sorting behavior and handling the toggling of the sort indicator yourself using the DoubleClickHeader event.

        private void ultraGrid1_InitializeLayout(object sender, Infragistics.Win.UltraWinGrid.InitializeLayoutEventArgs e)
        {
            UltraGridLayout layout = e.Layout;
            UltraGridOverride ov = layout.Override;

            // Turn off sorting. 
            ov.HeaderClickAction = HeaderClickAction.Select;

            // Turn off column selection
            ov.SelectTypeCol = SelectType.None;
        }

        private void ultraGrid1_DoubleClickHeader(object sender, DoubleClickHeaderEventArgs e)
        {
            switch (e.Header.Column.SortIndicator)
            {
                case SortIndicator.Ascending:
                    e.Header.Column.SortIndicator = SortIndicator.Descending;
                    break;
                case SortIndicator.None:
                case SortIndicator.Descending:
                    e.Header.Column.SortIndicator = SortIndicator.Ascending;
                    break;
                case SortIndicator.Disabled:
                    break;
            }
        }