Scenario

DevExpress by default gives you the functionality within the Model to group list views together based on a selected field and show a count of records within the Group Header as seen in the screenshot below.

A user can then expand each group to see each individual record. To give the user a better understanding and overview of the records we wish to add a group footer to each group and display a total of the Time In Days spent against each group.

Solution

Within the Module.Win project create a new blank View Controller and customise the code below as required within it to get the results you require.

/// <summary>
/// Called when [view controls created].
/// </summary>
protected override void OnViewControlsCreated()
{         
    base.OnViewControlsCreated();
 
    if (View.Id == "MyListView")
    {
        GridControl grid = (GridControl)View.Control;
        GridView view = (GridView)grid.FocusedView;
        view.Columns.View.OptionsSelection.MultiSelect = true;
        view.OptionsSelection.MultiSelectMode = GridMultiSelectMode.CellSelect;
        view.OptionsView.GroupFooterShowMode = GroupFooterShowMode.VisibleAlways;
 
        GridColumn timeValueColumn = view.Columns["TimeInDays"];
        GridGroupSummaryItem timeValueSummaryItem = new GridGroupSummaryItem();
        timeValueSummaryItem.FieldName = "TimeInDays";
        timeValueSummaryItem.SummaryType = SummaryItemType.Sum;
        timeValueSummaryItem.DisplayFormat = "Personnel Total (Days) = {0:n2}";
        timeValueSummaryItem.Tag = 1;
        timeValueSummaryItem.ShowInGroupColumnFooter = timeValueColumn;
        view.GroupSummary.Add(timeValueSummaryItem);
    }
}

Implementing the above code creates a group footer against each group and displays a count of the Time In Days of each record within the group.