How to Dynamically Read Item Names in a PivotGrid Calculated Item

Updated on Apr 23, 2026

Environment

Product Version	Product
2025.1+	RadPivotGrid for WinForms

Description

The standard approach for implementing a CalculatedItem requires hardcoding the group names passed to GetAggregateValue. For example, the built-in documentation demonstrates calling aggregateSummaryValues.GetAggregateValue("Andrew Fuller") with a string literal. This becomes impractical when the data source contains a dynamic set of values or when the same calculated item must work across different data sets.

How can I iterate over the available group names inside a CalculatedItem without knowing them in advance? How can I create a calculated item that automatically adapts to the data?

This KB also answers the following questions:

• How to enumerate sibling groups inside a CalculatedItem in RadPivotGrid?
• How to create a CalculatedItem that calculates an average of all groups?
• How to use the Coordinate property in IAggregateSummaryValues to discover group names?

Solution

The IAggregateSummaryValues interface exposes a Coordinate property of type Coordinate. This struct contains RowGroup and ColumnGroup properties, each of which is an IGroup. By navigating up to the Parent of the current group and iterating its Groups collection, you can discover sibling group names at runtime and pass them to GetAggregateValue.

Each IGroup exposes:

• Name—The group key value.
• Parent—The parent group in the hierarchy.
• Groups—The child groups (IReadOnlyList<IGroup>).
• Type—The group type (BottomLevel, GrandTotal, Subheading, Subtotal).

To determine whether a sibling group represents a regular data item or another calculated item, check if the group's Name is a CalculatedItem instance. This prevents the calculated item from including other calculated items in its own computation.

Implementing a Dynamic Calculated Item

The following example creates a calculated item that computes the average of all sibling groups dynamically:

C#

public class AverageAllItems : CalculatedItem
{
    protected override AggregateValue GetValue(IAggregateSummaryValues aggregateSummaryValues)
    {
        IGroup currentGroup = aggregateSummaryValues.Coordinate.ColumnGroup;
        IGroup parentGroup = currentGroup.Parent;

        if (parentGroup == null || !parentGroup.HasGroups)
        {
            return AggregateValue.ErrorAggregateValue;
        }

        List<AggregateValue> values = new List<AggregateValue>();

        foreach (IGroup sibling in parentGroup.Groups)
        {
            if (sibling.Name is CalculatedItem)
            {
                continue;
            }

            AggregateValue value = aggregateSummaryValues.GetAggregateValue(sibling.Name);
            if (value != null && !value.IsError())
            {
                values.Add(value);
            }
        }

        if (values.Count == 0)
        {
            return AggregateValue.ErrorAggregateValue;
        }

        double average = values.Average(v => v.ConvertOrDefault<double>());
        return new DoubleAggregateValue(average);
    }
}

VB.NET

Public Class AverageAllItems
    Inherits CalculatedItem

    Protected Overrides Function GetValue(aggregateSummaryValues As IAggregateSummaryValues) As AggregateValue
        Dim currentGroup As IGroup = aggregateSummaryValues.Coordinate.ColumnGroup
        Dim parentGroup As IGroup = currentGroup.Parent

        If parentGroup Is Nothing OrElse Not parentGroup.HasGroups Then
            Return AggregateValue.ErrorAggregateValue
        End If

        Dim values As New List(Of AggregateValue)()

        For Each sibling As IGroup In parentGroup.Groups
            If TypeOf sibling.Name Is CalculatedItem Then
                Continue For
            End If

            Dim value As AggregateValue = aggregateSummaryValues.GetAggregateValue(sibling.Name)
            If value IsNot Nothing AndAlso Not value.IsError() Then
                values.Add(value)
            End If
        Next

        If values.Count = 0 Then
            Return AggregateValue.ErrorAggregateValue
        End If

        Dim average As Double = values.Average(Function(v) v.ConvertOrDefault(Of Double)())
        Return New DoubleAggregateValue(average)
    End Function
End Class

Use aggregateSummaryValues.Coordinate.ColumnGroup when the calculated item is added to a column group description, and aggregateSummaryValues.Coordinate.RowGroup when it is added to a row group description. The group you navigate determines which axis siblings are iterated.

Adding the Calculated Item

C#

PropertyGroupDescription groupDescription = new PropertyGroupDescription();
groupDescription.PropertyName = "Salesperson";

AverageAllItems avgItem = new AverageAllItems();
avgItem.GroupName = "Average (All)";
groupDescription.CalculatedItems.Add(avgItem);

localProvider.ColumnGroupDescriptions.Add(groupDescription);

VB.NET

Dim groupDescription As New PropertyGroupDescription()
groupDescription.PropertyName = "Salesperson"

Dim avgItem As New AverageAllItems()
avgItem.GroupName = "Average (All)"
groupDescription.CalculatedItems.Add(avgItem)

localProvider.ColumnGroupDescriptions.Add(groupDescription)

Using Row Groups

When the calculated item belongs to a row group description, replace ColumnGroup with RowGroup:

C#

public class SumAllRowItems : CalculatedItem
{
    protected override AggregateValue GetValue(IAggregateSummaryValues aggregateSummaryValues)
    {
        IGroup currentGroup = aggregateSummaryValues.Coordinate.RowGroup;
        IGroup parentGroup = currentGroup.Parent;

        if (parentGroup == null || !parentGroup.HasGroups)
        {
            return AggregateValue.ErrorAggregateValue;
        }

        double sum = 0;

        foreach (IGroup sibling in parentGroup.Groups)
        {
            if (sibling.Name is CalculatedItem)
            {
                continue;
            }

            AggregateValue value = aggregateSummaryValues.GetAggregateValue(sibling.Name);
            if (value != null && !value.IsError())
            {
                sum += value.ConvertOrDefault<double>();
            }
        }

        return new DoubleAggregateValue(sum);
    }
}

VB.NET

Public Class SumAllRowItems
    Inherits CalculatedItem

    Protected Overrides Function GetValue(aggregateSummaryValues As IAggregateSummaryValues) As AggregateValue
        Dim currentGroup As IGroup = aggregateSummaryValues.Coordinate.RowGroup
        Dim parentGroup As IGroup = currentGroup.Parent

        If parentGroup Is Nothing OrElse Not parentGroup.HasGroups Then
            Return AggregateValue.ErrorAggregateValue
        End If

        Dim sum As Double = 0

        For Each sibling As IGroup In parentGroup.Groups
            If TypeOf sibling.Name Is CalculatedItem Then
                Continue For
            End If

            Dim value As AggregateValue = aggregateSummaryValues.GetAggregateValue(sibling.Name)
            If value IsNot Nothing AndAlso Not value.IsError() Then
                sum += value.ConvertOrDefault(Of Double)()
            End If
        Next

        Return New DoubleAggregateValue(sum)
    End Function
End Class

See Also

• Calculated Items
• Calculated Fields
• Custom Aggregation