Winforms – Devexpress Total Sum Summary cell is blank and wont display summary

devexpresssumsummarywinformsxtragrid

I have a Devexpress XtraGrid with a total summary cell in the footer.

The cell is displayed correctly, but there is no value in it.
I have:
Grid.OptionsView.ShowFooter = true and Grid.OptionsBehavior.AutoUpdateTotalSummary = true.

In the column where I want the total sum I have:
Col.SummaryItem.FieldName = col.FieldName and col.SummaryItem.SummaryType = Sum and col.SummaryItem.DIsplayFormat = ${0}

The summery cell never shows a value.
If right click on the summary cell and then select Sum the summary value shows up and works correctly. But I need to work without the user needing to right click on the cell and select Sum.
Any help would be appreciated. Thanks 🙂

Best Answer

The following code works fine to me, so I believe that there is something wrong in your source code:

using DevExpress.Data;
using DevExpress.XtraGrid;
//...
colUnitPrice.FieldName = "UnitPrice";
colUnitPrice.Name = "colUnitPrice";
colUnitPrice.Summary.AddRange(new GridSummaryItem[] {
    new GridColumnSummaryItem(SummaryItemType.Sum, "UnitPrice", "${0}")});

Please, check your source code again (don't forget to review the Total Summary article) or provide us with more details on this issue.

Related Solutions

.net – How to add a weighted average summary to a DevExpress XtraGrid

I ended up working this out, and will post my solution here in case others find it useful.

If a weighted average consists of both a value and a weight per row, then column that contains the value should have the weight GridColumn object assigned to its Tag property. Then, this event handler will do the rest:

private static void gridView_CustomSummaryCalculate(object sender, CustomSummaryEventArgs e)
{
    GridColumn weightColumn = ((GridSummaryItem)e.Item).Tag as GridColumn;

    if (weightColumn == null)
        return;

    switch (e.SummaryProcess)
    {
        case CustomSummaryProcess.Start:
        {
            e.TotalValue = new WeightedAverageCalculator();
            break;
        }
        case CustomSummaryProcess.Calculate:
        {
            double size = Convert.ToDouble(e.FieldValue);
            double weight = Convert.ToDouble(((GridView)sender).GetRowCellValue(e.RowHandle, weightColumn));

            ((WeightedAverageCalculator)e.TotalValue).Add(weight, size);
            break;
        }
        case CustomSummaryProcess.Finalize:
        {
            e.TotalValue = ((WeightedAverageCalculator)e.TotalValue).Value;
            break;
        }
    }
}

private sealed class WeightedAverageCalculator
{
    private double _sumOfProducts;
    private double _totalWeight;

    public void Add(double weight, double size)
    {
        _sumOfProducts += weight * size;
        _totalWeight += weight;
    }

    public double Value
    {
        get { return _totalWeight==0 ? 0 : _sumOfProducts / _totalWeight; }
    }
}

The code assumes that the underlying column values can be converted to doubles via Convert.ToDouble(object).

Get Result sum from two devexpress gridview’s Sum column

after both your Grids Are bound to DataSource, call the below method. However, Label cannot be updated if grids update via callbacks. in that case you need to use AspxCallback Panel, place 2 grids & label in Callback Panel, and PerformCallback on the CallbackPanel when grids need to be updated:

private void UpdateSummaryLabel(){
    double rate1 = double.Parse(grid1.GetTotalSummaryValue(grid1.TotalSummary["Rate", DevExpress.Data.SummaryItemType.Sum]).ToString());
    double rate2 = double.Parse(grid2.GetTotalSummaryValue(grid2.TotalSummary["Rate", DevExpress.Data.SummaryItemType.Sum]).ToString());

    label.Text = String.Format("{0:n2}", rate1 + rate2);
}

Best Answer

Related Solutions

.net – How to add a weighted average summary to a DevExpress XtraGrid

Get Result sum from two devexpress gridview’s Sum column

Related Topic