CustomSummaryEventArgs.SummaryProcess Property

Gets a value that indicates the data summary calculation stage.

Namespace : DevExpress.XamarinForms.DataGrid

Assembly : DevExpress.XamarinForms.Grid.dll

NuGet Package : DevExpress.XamarinForms.Grid

Declaration

csharp

public CustomSummaryProcess SummaryProcess { get; }

Property Value

Type	Description
CustomSummaryProcess

A value indicating the calculation stage.

Available values:

Name	Description
Start

Indicates that the process of custom summary calculation is about to start.

| | Calculate |

Indicates that custom summary calculation is in progress. This means the event is raised for a specific data row that contains the field value used to calculate the processed custom summary.

| | Finalize |

Indicates that the process of custom summary calculation is finished.

Remarks

The process of custom summary calculation consists of three stages.

Initialization - the SummaryProcess property is set to CustomSummaryProcess.Start and the DataGridView.CalculateCustomSummary event is raised once.
Calculation - the SummaryProcess property is set to CustomSummaryProcess.Calculate and the DataGridView.CalculateCustomSummary event occurs multiple times, once for each data row in the grid or group.
Finalization - the SummaryProcess property is set to CustomSummaryProcess.Finalize and the DataGridView.CalculateCustomSummary event is raised once.

Example

This example demonstrates how to use predefined aggregate functions and custom rule to calculate group and total summaries for grid columns.

Set the group summary to display the maximum Total value for each group of records.
Set the total summary to calculate the sum of values in the Total column.
Set the custom total summary to count the number of orders whose value in the Shipped column is false (to count orders that are not shipped).
XAML

xaml

<dxg:DataGridView x:Name="grid" ItemsSource="{Binding Orders}" 
                 CalculateCustomSummary="OnCalculateCustomSummary">
    <!-- ... -->
    <dxg:DataGridView.GroupSummaries>
        <dxg:GridColumnSummary FieldName="Total" Type="Max"/>
    </dxg:DataGridView.GroupSummaries>

    <dxg:DataGridView.TotalSummaries>
        <dxg:GridColumnSummary FieldName="Total" Type="Sum" 
                               DisplayFormat="Total: {0:C0}"/>
        <dxg:GridColumnSummary FieldName="Shipped" Type="Custom" 
                               DisplayFormat="Not Shipped: {0}"/>
    </dxg:DataGridView.TotalSummaries>
</dxg:DataGridView>

csharp

int count;
// ...

void OnCalculateCustomSummary(object sender, CustomSummaryEventArgs e) {
    if (e.FieldName.ToString () == "Shipped")
        if (e.IsTotalSummary){
            if (e.SummaryProcess == CustomSummaryProcess.Start) {
                count = 0;
            }
            if (e.SummaryProcess == CustomSummaryProcess.Calculate) {
                if (!(bool)e.FieldValue)
                    count++;
                e.TotalValue = count;
            }
        }
}