Summaries in Xamarin DataGrid (SfDataGrid)

The data grid supports to display the concise information about the bound data objects using summaries. The control provides the following summary types:

  • Caption Summary - Used to display the summary information in the caption of the group.
  • Group Summary - Used to display summary information of data objects in each group.
  • Table Summary - Used to display the summary information at top and/or bottom in SfDataGrid.

DataGrid with summary rows

Summary rows are represented by using the GridSummaryRow that hold summary information of columns in the SummaryColumns property . The SummaryColumns contains the collection of GridSummaryColumn which carries name, format, and summary aggregate type of the column.

Derive additional information from the data like sum, average, maximum, minimum, and count using summaries in the data grid. These summary values can be computed for groups or for the entire control using GridSummaryRow and GridSummaryColumn that implements ISummaryRow and ISummaryColumn interfaces.

NOTE

The Summary does not refresh with data. To update the summary for the newly added row, or for the modified summary column, set the SfDataGrid.View.LiveDataUpdateMode to LiveDataUpdateMode.AllowDataShaping or LiveDataUpdateMode.AllowSummaryUpdate.

Caption summaries

The data grid provides built-in support for caption summaries. The caption summary value calculated based on the records in a group. The summary information will be displayed in the caption of group.

The following screenshot shows the built-in caption summary of a group:

DataGrid with caption summary

Formatting built-in caption summary

By default, caption summary rows are displayed with the SfDataGrid.GroupCaptionTextFormat property.

Default group caption format is {ColumnName}: {Key} - {ItemsCount} Items.

  • ColumnName: Displays the name of the currently grouped column.
  • Key: Displays the key value of the group.
  • ItemsCount: Displays the number of items in a group.

DataGrid with formatting in caption summary row

The group caption text format can be customized by setting the SfDataGrid.GroupCaptionTextFormat property. The following code example illustrates how to customize group caption text in the data grid:

<sfGrid:SfDataGrid x:Name="dataGrid"
                   AutoGenerateColumns="True"
                   ColumnSizer="Star"
                   GroupCaptionTextFormat="{}{ColumnName}: {Key}">
//Customized group caption text
dataGrid.GroupCaptionTextFormat = "{ColumnName} : {Key}";

The following screenshot shows the outcome of the previous code:

DataGrid with formatting in caption summary row

Displaying summary for a row

Display summary information in a row by setting the GridGroupSummaryRow.ShowSummaryInRow property to true and define summary columns. You have to define the GridGroupSummaryRow.Title based on the GridSummaryColumn.Name property to format summary columns value in a row.

<sfGrid:SfDataGrid.CaptionSummaryRow>
    <sfGrid:GridGroupSummaryRow Title="Total Salary :{TotalSalary} for {ProductCount} members"
                           ShowSummaryInRow="True">
        <sfGrid:GridGroupSummaryRow.SummaryColumns>
            <sfGrid:GridSummaryColumn Name="TotalSalary"
                                      Format="{}{Sum:c}"
                                      MappingName="Salary"
                                      Format="{}{Count}"
                                      MappingName="Salary"
                                      SummaryType="CountAggregate" />
            </sfGrid:GridGroupSummaryRow.SummaryColumns>
        </sfGrid:GridGroupSummaryRow>
</sfGrid:SfDataGrid.CaptionSummaryRow>
GridGroupSummaryRow summaryRow = new GridGroupSummaryRow();
summaryRow.Title = "Total Salary:{TotalSalary} for {ProductCount} members";
summaryRow.ShowSummaryInRow = true;
summaryRow.SummaryColumns.Add(new GridSummaryColumn()
{
    Name = "TotalSalary",
    MappingName = "Salary",
    Format = "{Sum:c}",
    SummaryType = SummaryType.DoubleAggregate
});
summaryRow.SummaryColumns.Add(new GridSummaryColumn()
{
    Name = "ProductCount",
    MappingName = "Salary",
    Format = "{Count}",
    SummaryType = SummaryType.CountAggregate
});
sfGrid.CaptionSummaryRow= summaryRow;

The following screenshot shows the outcome for both values of ShowSummaryInRow to true:

DataGrid with customized caption summary row

Displaying summary for column

Display summary information in the column by setting the GridSummaryRow.ShowSummaryInRow to false and define summary columns. SfDataGrid.GridSummaryColumn is the object of GridSummaryRow.SummaryColumns collection that contains the following important properties:

  • Name: Defines name of the GridSummaryColumn to denote the GridSummaryColumn in GridSummaryRow with title.
  • MappingName: Defines the corresponding column name used for the summary calculation.
  • SummaryType: Defines the SummaryType (enum) property to define the aggregate type for the summary calculation.

The DataGrid control provides the following predefined aggregates:

  • CountAggregate
  • Int32Aggregate
  • DoubleAggregate

CustomAggregate defines the CustomAggregate class object when the summary type is set as Custom that calculates the custom summaries.

The Format defines the string property that formats the summary value and displays it. The Format property may contains two parts separated by a colon (:). First part denotes the aggregate function name, and second part denotes display format of the summary value.

Refer to the Formatting Summary section to know more about how to format summary, and Aggregate Types section to know about different summary types.

In the following code snippet, summary is defined for Salary column:

<sfGrid:SfDataGrid.CaptionSummaryRow>
    <sfGrid:GridSummaryRow Name="CaptionSummary" ShowSummaryInRow="False">
        <sfGrid:GridSummaryRow.SummaryColumns>
            <sfGrid:GridSummaryColumn Name="CaptionSummary"
                                      Format="{}{Sum}"
                                      MappingName="Salary"
                                      SummaryType="DoubleAggregate" />
        </sfGrid:GridSummaryRow.SummaryColumns>
    </sfGrid:GridSummaryRow>
</sfGrid:SfDataGrid.CaptionSummaryRow>
GridSummaryRow summaryRow = new GridSummaryRow();
summaryRow.ShowSummaryInRow = false;
summaryRow.SummaryColumns.Add(new GridSummaryColumn()
{
    Name = "CaptionSummary",
    MappingName = "Salary",
    Format = "{Sum:c}",
    SummaryType = SummaryType.DoubleAggregate
});
sfGrid.CaptionSummaryRow= summaryRow;

DataGrid with caption summary cells customized

NOTE

The CaptionSummaryColumn text will be aligned based on the GridColumn.TextAlignment.

Caption summary template

The data grid hosts any view(s) inside a caption summary for the entire row or for individual columns by loading a template.

Displaying template for a row

The template for a caption summary row can be set by using SfDataGrid.CaptionSummaryTemplate to customize it based on requirement.

Refer the below code example in which a label is loaded in the caption summary template of caption summary row.

  • xaml
  • <ContentPage.Resources>
        <ResourceDictionary>
          <local:DisplayBindingConverter x:Key="SummaryConverter" />
        </ResourceDictionary>
      </ContentPage.Resources>
    
      <sfgrid:SfDataGrid x:Name="dataGrid"
                       ItemsSource="{Binding OrdersInfo}">
    
    <sfgrid:SfDataGrid.CaptionSummaryTemplate>
       <DataTemplate>
         <StackLayout Orientation="Horizontal" BackgroundColor="Gray">
           <Image Source="{local:ImageResource UG_Sample.SalaryIcon.Png}"
                  Margin="0,5,0,5"
                 HorizontalOptions="Start"
                 VerticalOptions="Center"/>
           <Label Text="{Binding Converter={StaticResource SummaryConverter}, ConverterParameter = {x:Reference dataGrid} }"
                  TextColor="White"
                  FontSize="Large"
                  VerticalTextAlignment="Center"
                  HorizontalTextAlignment="Start"
                  LineBreakMode="NoWrap"
                  HorizontalOptions="FillAndExpand"
                  VerticalOptions="FillAndExpand">
             <Label.Style>
               <Style TargetType="Label">
                 <Setter Property="FontAttributes" Value="Bold, Italic" />
               </Style>
             </Label.Style>
           </Label>
           </StackLayout>
         </DataTemplate>
    </sfgrid:SfDataGrid.CaptionSummaryTemplate>
    <sfgrid:SfDataGrid.CaptionSummaryRow>
        <sfgrid:GridSummaryRow Name="CaptionSummary" ShowSummaryInRow="True" Title="Salary: {CaptionSummary}">
            <sfgrid:GridSummaryRow.SummaryColumns>
                <sfgrid:GridSummaryColumn Name="CaptionSummary"
                                          Format="{}{Sum}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
            </sfgrid:GridSummaryRow.SummaryColumns>
        </sfgrid:GridSummaryRow>
    </sfgrid:SfDataGrid.CaptionSummaryRow>
    </sfgrid:SfDataGrid>
  • c#
  • // To write a converter, follow the code example:
    
    public class GroupCaptionConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var data = value != null ? value as Group : null;
            if (data != null)
            {
                SfDataGrid dataGrid = (SfDataGrid)parameter;
                var summaryText = SummaryCreator.GetSummaryDisplayTextForRow((value as Group).SummaryDetails, dataGrid.View);
    
                return summaryText;
            }
            return null;
        }
    
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }

    DataGrid with template loaded for entire caption summary row

    NOTE

    The DataTemplateSelector can also be directly assigned to the CaptionSummaryTemplate.

    Displaying template for a column

    The template for a Caption summary column can be set by using GridSummaryColumn.Template to customize it based on requirement.

    Refer the below code example in which a label is loaded in the template of caption summary column.

  • xaml
  • <ContentPage.Resources>
            <ResourceDictionary>
                <local:GroupCaptionConverter x:Key="SummaryConverter" />
            </ResourceDictionary>
    </ContentPage.Resources>
    
    
    <sfgrid:SfDataGrid x:Name="dataGrid" AllowResizingColumn="True" AutoGenerateColumns="False" ColumnSizer="Star">
    
        <sfgrid:SfDataGrid.Columns>
            <sfgrid:GridTextColumn MappingName="OrderID" />
            <sfgrid:GridTextColumn MappingName="Salary" />
            <sfgrid:GridTextColumn MappingName="CustomerID" />
        </sfgrid:SfDataGrid.Columns>
       
        <sfgrid:SfDataGrid.CaptionSummaryRow>
            <sfgrid:GridSummaryRow Name="CaptionSummary" ShowSummaryInRow="False" Title="Salary: {CaptionSummary}">
                <sfgrid:GridSummaryRow.SummaryColumns>
                    <sfgrid:GridSummaryColumn Name="CaptionSummary" Format="{}{Sum}" MappingName="Salary"  
                                              SummaryType="DoubleAggregate" >
                        <sfgrid:GridSummaryColumn.Template>
    
                            <DataTemplate>
                                    <StackLayout Orientation="Horizontal" BackgroundColor="DarkCyan">
                                        <Image  PropertyChanged="Image_PropertyChanged" Margin="0,5,0,5"  
                                                HorizontalOptions="Start" 
                                                VerticalOptions="Center"/>
                                        <Label Text="{Binding Converter={StaticResource SummaryConverter}, 
                                                      ConverterParameter = {x:Reference dataGrid} }" 
                                                TextColor="White" FontSize="Small" 
                                                VerticalTextAlignment="Center"
                                                HorizontalTextAlignment="Start"
                                                LineBreakMode="NoWrap"
                                                HorizontalOptions="FillAndExpand"
                                                VerticalOptions="FillAndExpand">
                                            <Label.Style>
                                                <Style TargetType="Label">
                                                    <Setter Property="FontAttributes" Value="Bold, Italic" />
                                                </Style>
                                            </Label.Style>
                                        </Label>
                                    </StackLayout>
                                </DataTemplate>
    
                            </sfgrid:GridSummaryColumn.Template>
                        </sfgrid:GridSummaryColumn>
                    </sfgrid:GridSummaryRow.SummaryColumns>
                </sfgrid:GridSummaryRow>
            </sfgrid:SfDataGrid.CaptionSummaryRow> 
    
        </sfgrid:SfDataGrid>
  • c#
  • // To write a converter, follow the code example:
    
    
    public class GroupCaptionConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var data = value != null ? value as Group : null;
            if (data != null)
            {
                SfDataGrid dataGrid = (SfDataGrid)parameter;
                var summaryText = SummaryCreator.GetSummaryDisplayTextForRow((value as Group).SummaryDetails, dataGrid.View);
    
                return summaryText;
            }
            return null;
        }
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
    }

    DataGrid with template loaded for individual caption summary column

    Group summary

    Group summary values are calculated based on records in the group. The summary information will be displayed at the bottom of each group. You can view the group summary row by expanding the corresponding group header. The data grid adds any number of group summary row.

    Add group summary rows in the data grid by adding the GridGroupSummaryRow to SfDataGrid.GroupSummaryRows collection.

    Displaying summary in the row

    The summary information can be displayed in the row by setting the GridGroupSummaryRow.ShowSummaryInRow to true and by defining summary columns. You have to define the GridGroupSummaryRow.Title based on the GridGroupSummaryRow.Name property to format summary columns value in a row.

    Refer to Formatting Summary section to know more about how to format summary.

    <ContentPage x:Class="SummaryDemo.Summary"
                 xmlns="http://xamarin.com/schemas/2014/forms"
                 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                 xmlns:local="clr-namespace:SummaryDemo"
                 xmlns:sfgrid="clr-namespace:Syncfusion.SfDataGrid.XForms;assembly=Syncfusion.SfDataGrid.XForms">
        <sfgrid:SfDataGrid x:Name="dataGrid" AllowResizingColumn="True" AllowGroupExpandCollapse="True"
                           AutoGenerateColumns="True" 
                           ColumnSizer="Star">
    
        <sfgrid:SfDataGrid.GroupColumnDescriptions>
                <sfgrid:GroupColumnDescription ColumnName="Salary"  />
            </sfgrid:SfDataGrid.GroupColumnDescriptions>
    
            <sfgrid:SfDataGrid.GroupSummaryRows>
                <sfgrid:GridGroupSummaryRow ShowSummaryInRow="True" Title="Total Salary: {Salary} for {customerID} members">
                    
                    <sfgrid:GridGroupSummaryRow.SummaryColumns>
    
                        <sfgrid:GridSummaryColumn Name="Salary" 
                                                      MappingName="Salary" 
                                                      Format="{}{Sum}"
                                                      SummaryType="DoubleAggregate">
                        </sfgrid:GridSummaryColumn>
    
                        <sfgrid:GridSummaryColumn Name="customerID" 
                                                      MappingName="CustomerID" 
                                                      Format="{}{Count}"
                                                      SummaryType="CountAggregate">
                        </sfgrid:GridSummaryColumn>
    
                    </sfgrid:GridGroupSummaryRow.SummaryColumns>
                    
                </sfgrid:GridGroupSummaryRow>
            </sfgrid:SfDataGrid.GroupSummaryRows>
    
      </sfgrid:SfDataGrid>
    </ContentPage>
    this.dataGrid.GroupSummaryRows.Add(new GridGroupSummaryRow()
                {
                    ShowSummaryInRow = true,
                    Title = "Total Salary: {Salary} for {customerID} members",
                    SummaryColumns = new ObservableCollection<ISummaryColumn>()
                    {
                        new GridSummaryColumn()
                        {
                            Name="Salary",
                            MappingName="Salary",
                            SummaryType=SummaryType.DoubleAggregate,
                            Format="{Sum}"
                        },
                        new GridSummaryColumn()
                        {
                            Name="customerID",
                            MappingName="customerID",
                            Format="{Count}",
                            SummaryType=SummaryType.CountAggregate
                        }
                    }
                });

    DataGrid with group summary

    Displaying summary in the column

    The summary information can be displayed in the column by setting the GridGroupSummaryRow.ShowSummaryInRow to false and by defining summary columns. To calculate summary based on the column, specify the following properties:

    1. GridSummaryColumn.MappingName: Provides MappingName of the column (Property name of data object) that you want to calculate summary.
    2. GridSummaryColumn.SummaryType: Provides different built-in summary calculation functions for various types.
    3. GridSummaryColumn.Format: Provides format string for the summary based on support function name in the specified SummaryType.

    Refer to Formatting Summary section to know more about how to format summary and Aggregate Types section to know about different Summary Types.

    In the following code snippet, summary is defined for Salary and CustomerID columns:

    <ContentPage x:Class="SummaryDemo.Summary"
                 xmlns="http://xamarin.com/schemas/2014/forms"
                 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                 xmlns:local="clr-namespace:SummaryDemo"
                 xmlns:sfgrid="clr-namespace:Syncfusion.SfDataGrid.XForms;assembly=Syncfusion.SfDataGrid.XForms">
    
     <sfgrid:SfDataGrid x:Name="dataGrid" AllowResizingColumn="True"
                           AutoGenerateColumns="True" 
                           ColumnSizer="Star">
    
           <sfgrid:SfDataGrid.GroupSummaryRows>
                <sfgrid:GridGroupSummaryRow ShowSummaryInRow="False" >
                    
                    <sfgrid:GridGroupSummaryRow.SummaryColumns>
    
                        <sfgrid:GridSummaryColumn Name="Salary" 
                                                      MappingName="Salary" 
                                                      Format="{}{Sum}"
                                                      SummaryType="DoubleAggregate">
                        </sfgrid:GridSummaryColumn>
    
                        <sfgrid:GridSummaryColumn Name="customerID" 
                                                      MappingName="CustomerID" 
                                                      Format="Total members - {Count}"
                                                      SummaryType="CountAggregate">
                        </sfgrid:GridSummaryColumn>
    
                    </sfgrid:GridGroupSummaryRow.SummaryColumns>
                    
                </sfgrid:GridGroupSummaryRow>
            </sfgrid:SfDataGrid.GroupSummaryRows>
    
    
        </sfgrid:SfDataGrid>
    </ContentPage>
    this.dataGrid.GroupSummaryRows.Add(new GridGroupSummaryRow()
                {
                    ShowSummaryInRow = false,
                    SummaryColumns = new ObservableCollection<ISummaryColumn>()
                    {
                        new GridSummaryColumn()
                        {
                            Name="Salary",
                            MappingName="Salary",
                            SummaryType=SummaryType.DoubleAggregate,
                            Format="{Sum}"
                        },
                        new GridSummaryColumn()
                        {
                            Name="customerID",
                            MappingName="CustomerID",
                            Format="Total members - {Count:d}",
                            SummaryType=SummaryType.CountAggregate
                        }
                    }
                });

    DataGrid with customized summary for group summary cells

    Group summary template

    The data grid hosts any view(s) inside a group summary for the entire row or for individual columns by loading a template.

    Displaying template for a row

    The template for a group summary row can be set by using SfDataGrid.GroupSummaryTemplate to customize it based on requirement.

    Refer the below code example in which a label is loaded in the group summary template of group summary row.

  • xaml
  • <ContentPage.Resources>
            <ResourceDictionary>
                <local:GroupSummaryConverter x:Key="SummaryConverter" />
            </ResourceDictionary>
        </ContentPage.Resources>
    
      <sfgrid:SfDataGrid x:Name="dataGrid"
                       ItemsSource="{Binding OrdersInfo}">
    
           <sfgrid:SfDataGrid.GroupSummaryTemplate>
                <DataTemplate>
                    <StackLayout Orientation="Horizontal" BackgroundColor="Gray">
                    <Label Text="{Binding Converter={StaticResource SummaryConverter}, ConverterParameter = {x:Reference dataGrid} }"
                                               TextColor="White"
                                               FontSize="Large"
                                               VerticalTextAlignment="Center"
                                               HorizontalTextAlignment="Start"
                                               LineBreakMode="NoWrap"
                                               HorizontalOptions="FillAndExpand"
                                               VerticalOptions="FillAndExpand">
                        <Label.Style>
                            <Style TargetType="Label">
                                <Setter Property="FontAttributes" Value="Bold, Italic" />
                            </Style>
                        </Label.Style>
                    </Label>
                    </StackLayout>
                </DataTemplate>
           </sfgrid:SfDataGrid.GroupSummaryTemplate>
    
       <sfgrid:SfDataGrid.GroupSummaryRows>
                <sfgrid:GridGroupSummaryRow ShowSummaryInRow="True">
                    
                    <sfgrid:GridGroupSummaryRow.SummaryColumns>
    
                        <sfgrid:GridSummaryColumn Name="Salary" 
                                                      MappingName="Salary" 
                                                      Format="{}{Sum}"
                                                      SummaryType="DoubleAggregate">
                        </sfgrid:GridSummaryColumn>
    
                        <sfgrid:GridSummaryColumn Name="customerID" 
                                                      MappingName="CustomerID" 
                                                      Format="{}{Count}"
                                                      SummaryType="CountAggregate">
                        </sfgrid:GridSummaryColumn>
    
                    </sfgrid:GridGroupSummaryRow.SummaryColumns>
                    
                </sfgrid:GridGroupSummaryRow>
            </sfgrid:SfDataGrid.GroupSummaryRows>
    </sfgrid:SfDataGrid>
  • c#
  • // To write a converter, follow the code example:
    
    public class GroupSummaryConverter : IValueConverter
        {
    
            public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
            {
                var data = value != null ? value as SummaryRecordEntry : null;
                if (data != null)
                {
                    SfDataGrid dataGrid = (SfDataGrid)parameter;
                    
                    var summaryText = SummaryCreator.GetSummaryDisplayText(data,"Salary",dataGrid.View);
    
                    return "Total Salary:" + " " + summaryText.ToString();
                }
                return null;
            }
    
            public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
            {
                return null;
            }
        }

    DataGrid with template loaded for entire group summary row

    NOTE

    The DataTemplateSelector can also be directly assigned to the SfDataGrid.GroupSummaryTemplate.

    Displaying template for a column

    The template for a group summary column can be set by using GridSummaryColumn.Template to customize it based on requirement.

    Refer the below code example in which a label is loaded in the template of group summary column.

  • xaml
  • <ContentPage.Resources>
            <ResourceDictionary>
                <local:GroupSummaryConverter x:Key="SummaryConverter" />
            </ResourceDictionary>
    </ContentPage.Resources>
    
    
    <sfgrid:SfDataGrid x:Name="dataGrid" AllowResizingColumn="True" AutoGenerateColumns="False" ColumnSizer="Star">
    
        <sfgrid:SfDataGrid.Columns>
            <sfgrid:GridTextColumn MappingName="OrderID" />
            <sfgrid:GridTextColumn MappingName="Salary" />
            <sfgrid:GridTextColumn MappingName="CustomerID" />
            <sfgrid:GridTextColumn MappingName="Country" />
        </sfgrid:SfDataGrid.Columns>
       
         <sfgrid:SfDataGrid.GroupSummaryRows>
                <sfgrid:GridGroupSummaryRow ShowSummaryInRow="False" >
                    
                    <sfgrid:GridGroupSummaryRow.SummaryColumns>
    
                        <sfgrid:GridSummaryColumn Name="Salary"
                                                      MappingName="Salary" 
                                                      Format="{}{Sum}"
                                                      SummaryType="DoubleAggregate">
                            <sfgrid:GridSummaryColumn.Template>
                                <DataTemplate>
                                    <StackLayout Orientation="Horizontal" BackgroundColor="Gray">
                                        <Label Text="{Binding Converter={StaticResource SummaryConverter}, ConverterParameter = {x:Reference dataGrid} }"
                                               TextColor="White"
                                               FontSize="Large"
                                               VerticalTextAlignment="Center"
                                               HorizontalTextAlignment="Center"
                                               LineBreakMode="NoWrap"
                                               HorizontalOptions="FillAndExpand"
                                               VerticalOptions="FillAndExpand">
                                            <Label.Style>
                                                <Style TargetType="Label">
                                                    <Setter Property="FontAttributes" Value="Bold, Italic" />
                                                </Style>
                                            </Label.Style>
                                        </Label>
                                    </StackLayout>
                                </DataTemplate>
                            </sfgrid:GridSummaryColumn.Template>
                            
                        </sfgrid:GridSummaryColumn>
                        </sfgrid:GridGroupSummaryRow.SummaryColumns>
                    
                </sfgrid:GridGroupSummaryRow>
            </sfgrid:SfDataGrid.GroupSummaryRows>
    
        </sfgrid:SfDataGrid>
  • c#
  • // To write a converter, follow the code example:
    
    
     public class GroupSummaryConverter : IValueConverter
        {
    
            public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
            {
                var data = value != null ? value as SummaryRecordEntry : null;
                if (data != null)
                {
                    SfDataGrid dataGrid = (SfDataGrid)parameter;
                    
                    var summaryText = SummaryCreator.GetSummaryDisplayText(data,"Salary",dataGrid.View);
    
                    return summaryText.ToString();
                }
                return null;
            }
    
            public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
            {
                return null;
            }
        }

    DataGrid with template loaded for individual group summary cell

    Table summaries

    The data grid provides built-in support for table summaries. The table summary value is calculated based on all records in the control.

    You can add table summary row in the data grid by adding the GridTableSummaryRow to the SfDataGrid.TableSummaryRows collection.

    The following screenshot illustrates table summary rows in the data grid:

    DataGrid with table summary

    <sfGrid:SfDataGrid.TableSummaryRows>
        <sfGrid:GridTableSummaryRow Title="Total Salary :{TotalSalary} for {ProductCount} members"
                                    Position="Top"
                                    ShowSummaryInRow="True">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                <sfGrid:GridSummaryColumn Name="ProductCount"
                                          Format="{}{Count}"
                                          MappingName="Salary"
                                          SummaryType="CountAggregate" />
                </sfGrid:GridTableSummaryRow.SummaryColumns>
            </sfGrid:GridTableSummaryRow>
        <sfGrid:GridTableSummaryRow Position="Top" ShowSummaryInRow="True">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                </sfGrid:GridTableSummaryRow.SummaryColumns>
            </sfGrid:GridTableSummaryRow>
    </sfGrid:SfDataGrid.TableSummaryRows>
    GridTableSummaryRow summaryRow1 = new GridTableSummaryRow();
    summaryRow1.Title = "Total Salary:{TotalSalary} for {ProductCount} members";
    summaryRow1.ShowSummaryInRow = true;
    summaryRow1.Position = Position.Top;
    summaryRow1.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    summaryRow1.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "ProductCount",
        MappingName = "Salary",
        Format = "{Count}",
        SummaryType = SummaryType.CountAggregate
    });
    sfGrid.TableSummaryRows.Add(summaryRow1);
    
    GridTableSummaryRow summaryRow2 = new GridTableSummaryRow();
    summaryRow2.ShowSummaryInRow = false;
    summaryRow2.Position = Position.Top;
    summaryRow2.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{Sum}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.TableSummaryRows.Add(summaryRow2);

    DataGrid with table summary

    Displaying summary in a row

    Display summary information in a row by setting the GridTableSummaryRow.ShowSummaryInRow to true and define summary columns. You have to define the GridTableSummaryRow.Title based on the GridSummaryColumn.Name property to format summary columns values in a row.

    <sfGrid:SfDataGrid.TableSummaryRows>
        <sfGrid:GridTableSummaryRow Title="Total Salary :{TotalSalary} for {ProductCount} members"
                                    ShowSummaryInRow="True">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                <sfGrid:GridSummaryColumn Name="ProductCount"
                                          Format="{}{Count}"
                                          MappingName="Salary"
                                          SummaryType="CountAggregate" />
                </sfGrid:GridTableSummaryRow.SummaryColumns>
            </sfGrid:GridTableSummaryRow>
    </sfGrid:SfDataGrid.TableSummaryRows>
    GridTableSummaryRow summaryRow = new GridTableSummaryRow();
    summaryRow.Title = "Total Salary:{TotalSalary} for {ProductCount} members";
    summaryRow.ShowSummaryInRow = true;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "ProductCount",
        MappingName = "Salary",
        Format = "{Count}",
        SummaryType = SummaryType.CountAggregate
    });
    sfGrid.TableSummaryRows.Add(summaryRow);

    The following screenshot shows the table summary row if ShowSummaryInRow is true:

    DataGrid with customized table summary for entire row

    Displaying summary in a column

    Display summary information in a column by setting GridTableSummaryRow.ShowSummaryInRow to false and defining summary columns. GridSummaryColumn is the object of GridTableSummaryRow.SummaryColumns collection that contains the following important properties:

    • Name: Defines name of the GridSummaryColumn to denote the GridSummaryColumn in GridTableSummaryRow with title.
    • MappingName: Defines the corresponding column name for the summary calculation.
    • SummaryType: Defines the SummaryType (enum) property to define the aggregate type for the summary calculation.

    The data grid control provides the following predefined aggregates:

    • CountAggregate
    • Int32Aggregate
    • DoubleAggregate

    CustomAggregate defines the CustomAggregate class object when the summary type is set as Custom that calculates custom summaries.

    The Format defines the string property that formats the summary value and displays it. The Format property may contains two parts that are separated by a colon (:). First part denotes the aggregate function name, and second part denotes display format of the summary value.

    Refer to the Formatting Summary section to know more about how to format summary and Aggregate Types section to know about different summary types.

    In the following code snippet, summary is defined for Salary column:

    <sfGrid:SfDataGrid.TableSummaryRows>
        <sfGrid:GridTableSummaryRow Name="TableSummary" ShowSummaryInRow="False">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TableSummary"
                                          Format="{}{Sum}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
            </sfGrid:GridTableSummaryRow.SummaryColumns>
        </sfGrid:GridTableSummaryRow>
    </sfGrid:SfDataGrid.TableSummaryRows>
    GridTableSummaryRow summaryRow = new GridTableSummaryRow();
    summaryRow.ShowSummaryInRow = false;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TableSummary",
        MappingName = "Salary",
        Format = "{Sum}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.TableSummaryRows.Add(summaryRow);

    The following screenshot shows the table summary row if ShowSummaryInRow is false.

    DataGrid with customized table summary for individual cells

    Positioning TableSummaryRows

    The data grid add table summary rows either at top or bottom positions using the GridTableSummaryRow.Position property.

    <sfGrid:SfDataGrid.TableSummaryRows>
        <sfGrid:GridTableSummaryRow Position="Top"
                                    ShowSummaryInRow="False">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                </sfGrid:GridTableSummaryRow.SummaryColumns>
            </sfGrid:GridTableSummaryRow>
        <sfGrid:GridTableSummaryRow Position="Bottom"
                                    ShowSummaryInRow="True"
                                    Title="Total Salary :{TotalSalary} for {ProductCount} members">
            <sfGrid:GridTableSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                <sfGrid:GridSummaryColumn Name="ProductCount"
                                          Format="{}{Count}"
                                          MappingName="Salary"
                                          SummaryType="CountAggregate" />
            </sfGrid:GridTableSummaryRow.SummaryColumns>
        </sfGrid:GridTableSummaryRow>
    </sfGrid:SfDataGrid.TableSummaryRows>
    GridTableSummaryRow topSummaryRow = new GridTableSummaryRow();
    topSummaryRow.Position = Position.Top;
    topSummaryRow.ShowSummaryInRow = false;
    topSummaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{Sum}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.TableSummaryRows.Add(topSummaryRow);
    
    GridTableSummaryRow bottomSummaryRow = new GridTableSummaryRow();
    bottomSummaryRow.Position = Position.Bottom;
    bottomSummaryRow.Title = "Total Salary:{TotalSalary} for {ProductCount} members";
    bottomSummaryRow.ShowSummaryInRow = true;
    bottomSummaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    bottomSummaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "ProductCount",
        MappingName = "Salary",
        Format = "{Count}",
        SummaryType = SummaryType.CountAggregate
    });
    sfGrid.TableSummaryRows.Add(bottomSummaryRow);

    The below screenshot illustrates the positioning of table summary rows in SfDataGrid.

    Customizing table summary row position in a DataGrid

    Table summary template

    The data grid hosts any view(s) inside a table summary for the entire row or for individual columns by loading a template.

    Displaying template for a row

    The template for a table summary row can be set by using SfDataGrid.TableSummaryTemplate and it can be customized based on the requirement.

    Refer the below code example in which a label is loaded in the table summary template of table summary row.

  • xaml
  • <ContentPage.Resources>
            <ResourceDictionary>
                <local:TableSummaryConverter x:Key="SummaryConverter" />
            </ResourceDictionary>
        </ContentPage.Resources>
        <StackLayout>
            <sfgrid:SfDataGrid x:Name="dataGrid"
                               ItemsSource="{Binding OrdersInfo}"
                               AutoGenerateColumns="False"
                               AllowEditing="True"
                               NavigationMode="Cell"
                               SelectionMode="Single"
                               ColumnSizer="Star">
                <sfgrid:SfDataGrid.Columns>
                    <sfgrid:GridNumericColumn MappingName="OrderID" />
                    <sfgrid:GridTextColumn MappingName="EmployeeID" />
                    <sfgrid:GridTextColumn MappingName="FirstName"  />
                    <sfgrid:GridTextColumn MappingName="LastName"  />
                </sfgrid:SfDataGrid.Columns>
                <sfgrid:SfDataGrid.TableSummaryTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <StackLayout Orientation="Horizontal" BackgroundColor="Gray">
                                <Label Text="{Binding Converter={StaticResource SummaryConverter}, ConverterParameter = {x:Reference dataGrid} }"
                                       TextColor="White"
                                       FontSize="Large"
                                       VerticalTextAlignment="Center"
                                       HorizontalTextAlignment="Start"
                                       LineBreakMode="NoWrap"
                                       HorizontalOptions="FillAndExpand"
                                       VerticalOptions="FillAndExpand">
                                    <Label.Style>
                                        <Style TargetType="Label">
                                            <Setter Property="FontAttributes" Value="Italic" />
                                        </Style>
                                    </Label.Style>
                                </Label>
                            </StackLayout>
                        </ViewCell>
                    </DataTemplate>
                </sfgrid:SfDataGrid.TableSummaryTemplate>
                <sfgrid:SfDataGrid.TableSummaryRows>
                    <sfgrid:GridTableSummaryRow Title="Total Salary :{TotalSalary} for {ProductCount} members"
                                                Position="Bottom"
                                                ShowSummaryInRow="True">
                        <sfgrid:GridTableSummaryRow.SummaryColumns>
                            <sfgrid:GridSummaryColumn Name="TotalSalary"
                                                      Format="{}{Sum:c}"
                                                      MappingName="OrderID"
                                                      SummaryType="DoubleAggregate" />
                        </sfgrid:GridTableSummaryRow.SummaryColumns>
                    </sfgrid:GridTableSummaryRow>
                </sfgrid:SfDataGrid.TableSummaryRows>
            </sfgrid:SfDataGrid>
        </StackLayout>
  • c#
  • public class TableSummaryConverter : IValueConverter
        {
            public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
            {
                var data = value != null ? value as SummaryRecordEntry : null;
                if (data != null)
                {
                    SfDataGrid dataGrid = (SfDataGrid)parameter;
                    var summaryText = SummaryCreator.GetSummaryDisplayText(data, "OrderID", dataGrid.View);
                    return "Total Value:" + " " + summaryText.ToString();
                }
    
                return null;
            }
    
            public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
            {
                return null;
            }
        }

    Table summary template in a row

    Displaying template for a column

    The template for a table summary column can be set by using GridSummaryColumn.Template and it can be customized based on the requirement.

    Refer the below code example in which a label is loaded in the template of table summary column.

  • xaml
  • <ContentPage.Resources>
            <ResourceDictionary>
                <local:TableSummaryConverter x:Key="SummaryConverter" />
            </ResourceDictionary>
        </ContentPage.Resources>
        <StackLayout>
            <sfgrid:SfDataGrid x:Name="dataGrid"
                               ItemsSource="{Binding OrdersInfo}"
                               AutoGenerateColumns="False"
                               AllowEditing="True"
                               NavigationMode="Cell"
                               SelectionMode="Single"
                               ColumnSizer="Star">
                <sfgrid:SfDataGrid.Columns>
                    <sfgrid:GridNumericColumn MappingName="OrderID" />
                    <sfgrid:GridTextColumn MappingName="EmployeeID" />
                    <sfgrid:GridTextColumn MappingName="FirstName" />
                    <sfgrid:GridTextColumn MappingName="LastName" />
                </sfgrid:SfDataGrid.Columns>
                <sfgrid:SfDataGrid.TableSummaryRows>
                    <sfgrid:GridTableSummaryRow Title="Total Salary :{TotalSalary} for {ProductCount} members"
                                                Position="Bottom"
                                                ShowSummaryInRow="False">
                            <sfgrid:GridTableSummaryRow.SummaryColumns>
                                <sfgrid:GridSummaryColumn Name="TotalSalary"
                                                          Format="{}{Sum:c}"
                                                          MappingName="OrderID"
                                                          SummaryType="DoubleAggregate" >
                                    <sfgrid:GridSummaryColumn.Template>
                                     <DataTemplate>
                                        <StackLayout Orientation="Horizontal" BackgroundColor="Crimson">
                                            <Label Text="{Binding Converter={StaticResource SummaryConverter}, ConverterParameter = {x:Reference dataGrid} }"
                                                   TextColor="White"
                                                   FontSize="Large"
                                                   VerticalTextAlignment="Center"
                                                   HorizontalTextAlignment="Start"
                                                   LineBreakMode="NoWrap"
                                                   HorizontalOptions="FillAndExpand"
                                                   VerticalOptions="FillAndExpand">
                                                <Label.Style>
                                                    <Style TargetType="Label">
                                                        <Setter Property="FontAttributes" Value="Italic" />
                                                    </Style>
                                                </Label.Style>
                                            </Label>
                                        </StackLayout>
                                     </DataTemplate>
                                    </sfgrid:GridSummaryColumn.Template>
                                </sfgrid:GridSummaryColumn>
                            </sfgrid:GridTableSummaryRow.SummaryColumns>
                        </sfgrid:GridTableSummaryRow>
                </sfgrid:SfDataGrid.TableSummaryRows>            
            </sfgrid:SfDataGrid>
        </StackLayout>
  • c#
  • // To write a converter, follow the code example:
    
      public class TableSummaryConverter : IValueConverter
        {
            public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
            {
                var data = value != null ? value as SummaryRecordEntry : null;
                if (data != null)
                {
                    SfDataGrid dataGrid = (SfDataGrid)parameter;
                    var summaryText = SummaryCreator.GetSummaryDisplayText(data, "OrderID", dataGrid.View);
    
                    return summaryText.ToString();
                }
    
                return null;
            }
    
            public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
            {
                return null;
            }    
        }

    Table summary template in a column

    NOTE

    The DataTemplateSelector can also be directly assigned to the SfDataGrid.TableSummaryTemplate.

    Formatting summary

    In the following sections, the formatting is explained using the CaptionSummary. However, the formatting can also be applied for TableSummaries.

    Defining summary function

    In the following code snippet, the Format property is defined to display sum of Salary by specifying the function name inside curly braces:

    <sfGrid:SfDataGrid.CaptionSummaryRow>
        <sfGrid:GridSummaryRow ShowSummaryInRow="False">
            <sfGrid:GridSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="CaptionSummary"
                                          Format="{}{Sum}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
            </sfGrid:GridSummaryRow.SummaryColumns>
        </sfGrid:GridSummaryRow>
    </sfGrid:SfDataGrid.CaptionSummaryRow>
    GridSummaryRow summaryRow = new GridSummaryRow();
    summaryRow.ShowSummaryInRow = false;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "CaptionSummary",
        MappingName = "Salary",
        Format = "{Sum}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.CaptionSummaryRow= summaryRow;

    Formatting summary in a DataGrid

    Formatting summary value

    Format the summary value by setting the appropriate format after the aggregate function followed by a colon(:) in the GridSummaryColumn.Format property.

    In the following code snippet Salary column summary is formatted using c format specifier. Refer to here to know about how to set different formats.

    <sfGrid:SfDataGrid.CaptionSummaryRow>
        <sfGrid:GridSummaryRow ShowSummaryInRow="False">
            <sfGrid:GridSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="CaptionSummary"
                                          Format="{}{Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
            </sfGrid:GridSummaryRow.SummaryColumns>
        </sfGrid:GridSummaryRow>
    </sfGrid:SfDataGrid.CaptionSummaryRow>
    GridSummaryRow summaryRow = new GridSummaryRow();
    summaryRow.ShowSummaryInRow = false;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "CaptionSummary",
        MappingName = "Salary",
        Format = "{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.CaptionSummaryRow= summaryRow;

    Formatting summary value in a DataGrid

    Displaying additional content in summary

    Append additional content with summary value using the GridSummaryColumn.Format property.

    In the following code snippet Total: text is appended before summary value:

    <sfGrid:SfDataGrid.CaptionSummaryRow>
        <sfGrid:GridSummaryRow ShowSummaryInRow="False">
            <sfGrid:GridSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="CaptionSummary"
                                          Format="Total: {Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
            </sfGrid:GridSummaryRow.SummaryColumns>
        </sfGrid:GridSummaryRow>
    </sfGrid:SfDataGrid.CaptionSummaryRow>
    GridSummaryRow summaryRow = new GridSummaryRow();
    summaryRow.ShowSummaryInRow = false;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "CaptionSummary",
        MappingName = "Salary",
        Format = "Total:{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.CaptionSummaryRow= summaryRow;

    Displaying additional content in summary in a DataGrid

    Formatting summary for a row using Title property

    Format the summary value for a row using the GridSummaryRow.Title when ShowSummaryInRow set to true.

    <sfGrid:SfDataGrid.CaptionSummaryRow>
        <sfGrid:GridSummaryRow Title="Total Salary:{TotalSalary} for {ProductCount} members" ShowSummaryInRow="True">
            <sfGrid:GridSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="TotalSalary"
                                          Format="{}{Sum:c}"
                                          MappingName="Salary"
                                          SummaryType="DoubleAggregate" />
                <sfGrid:GridSummaryColumn Name="ProductCount"
                                          Format="{}{Count}"
                                          MappingName="Salary"
                                           SummaryType="CountAggregate" />
            </sfGrid:GridSummaryRow.SummaryColumns>
        </sfGrid:GridSummaryRow>
    </sfGrid:SfDataGrid.CaptionSummaryRow>
    GridSummaryRow summaryRow = new GridSummaryRow();
    summaryRow.Title = "Total Salary:{TotalSalary} for {ProductCount} members";
    summaryRow.ShowSummaryInRow = true;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "TotalSalary",
        MappingName = "Salary",
        Format = "{}{Sum:c}",
        SummaryType = SummaryType.DoubleAggregate
    });
    summaryRow.SummaryColumns.Add(new GridSummaryColumn()
    {
        Name = "ProductCount",
        MappingName = "Salary",
        Format = "{Count}",
        SummaryType = SummaryType.DoubleAggregate
    });
    sfGrid.CaptionSummaryRow= summaryRow;

    Formatting summary using title property

    NOTE

    Setting the SummaryColumn.Format property to {Sum:c} throws an exception since the compiler treats it like how we set binding to a string, since the syntax is the same. But here we are trying to set the culture format for the string. Hence set the format as Format = “{}{Sum:c}” when setting the format in XAML.

    Aggregate types

    Specify different summary aggregate types by using the GridSummaryColumn.SummaryType property, and use the built-in function in GridSummaryColumn.Format.

    List of predefined aggregate types and its built-in functions are as follows:

    Aggregate Type Built-in function
    CountAggregate Count
    Int32Aggregate Count, max, min, average, and sum.
    DoubleAggregate Count, max, min, average, and sum.
    Custom Used for custom summaries

    NOTE

    The above aggregate types can be applied for both CaptionSummaries and TableSummaries.

    Custom summaries

    The data grid implements your own aggregate functions when the built-in aggregate functions do not meet your requirement.

    Summary values can be calculated based on custom logic using the GridSummaryColumn.CustomAggregate property.

    Implementing custom aggregate

    1. Create a custom aggregate class by deriving from ISummaryAggregate interface.
    2. In the CalculateAggregateFunc() method, you have to calculate the summary and assign it to the property.

    In the following code snippet, Standard Deviation is calculated for quantity of products:

  • c#
  • public class CustomAggregate : ISummaryAggregate
    {
        public CustomAggregate()
        {
        }
        public double StdDev { get; set; }
        public Action<System.Collections.IEnumerable, string, System.ComponentModel.PropertyDescriptor> CalculateAggregateFunc()
        {
            return (items, property, pd) =>
            {
                var enumerableItems = items as IEnumerable<OrderInfo>;
                if (pd.Name == "StdDev")
                {
                    this.StdDev = enumerableItems.StdDev<OrderInfo>(q => q.OrderID);
                }
            };
        }
    }
    
    public static class LinqExtensions
    {
        public static double StdDev<T>(this IEnumerable<T> values, Func<T, double?> selector)
        {
            double value = 0;
            var count = values.Count();
            if (count > 0)
            {
                double? avg = values.Average(selector);
                double sum = values.Select(selector).Sum(d =>
                {
                    if (d.HasValue)
                    {
                        return Math.Pow(d.Value - avg.Value, 2);
                    }
                    return 0.0;
                });
                value = Math.Sqrt((sum) / (count - 1));
            }
            return value;
        }
    }

    Assign the custom aggregate to GridSummaryColumn.CustomAggregate property and set the SummaryType as Custom. GridSummaryColumn.Format property is defined based on property name in custom aggregate StdDev.

    <sfGrid:SfDataGrid.CaptionSummaryRow>
        <sfGrid:GridSummaryRow Title="Standard Deviation:{CaptionSummary}" ShowSummaryInRow = "True">                                                     
            <sfGrid:GridSummaryRow.SummaryColumns>
                <sfGrid:GridSummaryColumn Name="CaptionSummary"
                                          CustomAggregate="{StaticResource customAggregate}"
                                          Format="{}{StdDev}"
                                          MappingName="OrderID"
                                          SummaryType="Custom" />
            </sfGrid:GridSummaryRow.SummaryColumns>
        </sfGrid:GridSummaryRow>
    </sfGrid:SfDataGrid.CaptionSummaryRow>
    GridSummaryRow summaryRow = new GridSummaryRow();
    summaryRow.Title = "Standard Deviation:{CaptionSummary}";
    summaryRow.ShowSummaryInRow = true;
    summaryRow.SummaryColumns.Add(new GridSummaryColumn
    {
        Name = "CaptionSummary",
        CustomAggregate  = new CustomAggregate(),
        MappingName = "OrderID",
        Format = "{StdDev}",
        SummaryType = Syncfusion.Data.SummaryType.Custom
    });
    dataGrid.CaptionSummaryRow = summaryRow;

    DataGrid with custom aggregate

    NOTE

    The above custom summaries section is explained using CaptionSummary but the custom summaries can be also applied for TableSummaries.

    Overriding summary renderer

    Each summary cell in the data grid is associated with its own cell renderer. The data grid allows to extend this renderer to customize the grid cells based on your requirement. Customization can be applied by overriding the available virtual methods in the each cell renderer.

    Each summary has a specific key using which the custom summary renderer can be registered to the SfDataGrid.CellRenderers collection. Remove the key from collection and add a new entry with the same key along with the instance of custom renderer to register.

    Types of summary Renderer Key
    Table summary GridTableSummaryCellRenderer TableSummary
    Caption summary GridCaptionSummaryCellRenderer CaptionSummary
    Group summary GridSummaryCellRenderer GroupSummary

    Customizing table summary

    The data grid allows customizing the table summary by extending the GridTableSummaryCellRenderer class.

    NOTE

    By default, LoadUIView property of GridColumn is false for android. Hence, OnInitializeDisplayView() will not be called.

    To customize the table summary, follow the code example:

  • c#
  • // To remove default summary and Add custom summary.
    
    public class Summary : ContentPage
    {
        public Summary()
        {
            InitializeComponent();
            dataGrid.CellRenderers.Remove("TableSummary");
            dataGrid.CellRenderers.Add("TableSummary", new GridTableSummaryCellRendererExt());
        }
    }
    
    public class GridTableSummaryCellRendererExt : GridTableSummaryCellRenderer
    {
        public GridTableSummaryCellRendererExt()
        {
        }
    
        public override void OnInitializeDisplayView(DataColumnBase dataColumn, SfLabel view)
        {
            base.OnInitializeDisplayView(dataColumn, view);
            view.HorizontalTextAlignment = TextAlignment.Center;
            view.BackgroundColor = Color.DarkCyan;
            view.FontSize = 16;
            view.TextColor = Color.White;
    
        }
    }

    The following screenshot shows the final outcome upon execution of the above code.

    Customize table summary using custom cell renderer

    Customizing caption summary

    The data grid customizes the caption summary by overriding the GridCaptionSummaryCellRenderer.

    NOTE

    By default, LoadUIView property of GridColumn is false for android. Hence, OnInitializeDisplayView() will not be called.

    <sfgrid:SfDataGrid x:Name="dataGrid"      
                        AllowResizingColumn="True"
                        AutoGenerateColumns="False" 
                        ColumnSizer="Star">
    
            <sfgrid:SfDataGrid.Columns>
                <sfgrid:GridTextColumn MappingName="OrderID" LoadUIView="True" />
                <sfgrid:GridTextColumn MappingName="Salary" />
                <sfgrid:GridTextColumn MappingName="CustomerID" />
                
                <sfgrid:GridTextColumn MappingName="Freight" />
                <sfgrid:GridTextColumn MappingName="Country" />
            </sfgrid:SfDataGrid.Columns>
    
            <sfgrid:SfDataGrid.GroupColumnDescriptions>
                <sfgrid:GroupColumnDescription ColumnName="CustomerID"  />
            </sfgrid:SfDataGrid.GroupColumnDescriptions>
    </sfgrid:SfDataGrid>
    // To remove default summary and Add custom summary.
    
    public class Summary : ContentPage
    {
        public Summary()
        {
            InitializeComponent();
            dataGrid.CellRenderers.Remove("CaptionSummary");
            dataGrid.CellRenderers.Add("CaptionSummary", new GridCaptionSummaryCellRendererExt());
            dataGrid.GroupCaptionTextFormat = "{ColumnName} is Grouped by {Key} with Count- {ItemsCount}";
        }
    }
    
    public class GridCaptionSummaryCellRendererExt : GridCaptionSummaryCellRenderer
    {
        public GridCaptionSummaryCellRendererExt()
        {
        }
    
        public override void OnInitializeDisplayView(DataColumnBase dataColumn, SfLabel view)
        {
            base.OnInitializeDisplayView(dataColumn, view);
            view.HorizontalTextAlignment = TextAlignment.Center;
            view.BackgroundColor = Color.DarkCyan;
            view.FontAttributes = FontAttributes.Bold;
            view.FontSize = 16;
            view.TextColor = Color.White;
        }
    }

    Customize caption summary using custom cell renderer

    Customizing group summary

    The data grid customizes the group summary by overriding the GridGroupSummaryCellRenderer.

    NOTE

    By default, LoadUIView property of GridColumn is false for android. Hence, OnInitializeDisplayView() will not be called.

    <sfgrid:SfDataGrid x:Name="dataGrid"      
                       AutoGenerateColumns="False" 
                       ItemsSource="{Binding OrdersInfo}">
    
        <sfgrid:SfDataGrid.Columns>
            <sfgrid:GridTextColumn MappingName="OrderID" LoadUIView="True" Width="85" />
            <sfgrid:GridTextColumn MappingName="Salary" LoadUIView="True" Width="90"/>
            <sfgrid:GridTextColumn MappingName="CustomerID" LoadUIView="True" Width="150"/>
            <sfgrid:GridTextColumn MappingName="Country" LoadUIView="True" Width="90"/>
        </sfgrid:SfDataGrid.Columns>
    
        <sfgrid:SfDataGrid.GroupColumnDescriptions>
            <sfgrid:GroupColumnDescription ColumnName="Salary"  />
        </sfgrid:SfDataGrid.GroupColumnDescriptions>
    </sfgrid:SfDataGrid>
    public partial class MainPage : ContentPage
    {
        public MainPage()
        {
            InitializeComponent();
    
            // To remove default summary and Add custom summary.
            dataGrid.CellRenderers.Remove("GroupSummary");
            dataGrid.CellRenderers.Add("GroupSummary", new GridGroupSummaryCellRendererExt());
    
            dataGrid.GroupSummaryRows.Add(new GridGroupSummaryRow()
            {
                ShowSummaryInRow = true,
                Title = "Total Salary: {Salary} for {customerID} members",
                SummaryColumns = new ObservableCollection<ISummaryColumn>()
                {
                    new GridSummaryColumn()
                    {
                        Name="Salary",
                        MappingName="Salary",
                        SummaryType=SummaryType.DoubleAggregate,
                        Format="{Sum}"
                    },
                    new GridSummaryColumn()
                    {
                        Name="customerID",
                        MappingName="customerID",
                        Format="{Count}",
                        SummaryType=SummaryType.CountAggregate
                    }
                }
            });
        }
    }
    
    // Custom CellRenderer
    public class GridGroupSummaryCellRendererExt : GridGroupSummaryCellRenderer
    {
        public GridGroupSummaryCellRendererExt()
        {
        }
    
        public override void OnInitializeDisplayView(DataColumnBase dataColumn, SfLabel view)
        {
            base.OnInitializeDisplayView(dataColumn, view);
            base.OnInitializeDisplayView(dataColumn, view);
            view.HorizontalTextAlignment = TextAlignment.Center;
            view.BackgroundColor = Color.Gray;
            view.FontAttributes = FontAttributes.Italic;
            view.FontSize = 20;
            view.TextColor = Color.White;
        }
    }

    Customize group summary using custom cell renderer

    You can download the sample demo here .