StatResultConverter Class
See Also  Members   Example 
Xceed.Wpf.DataGrid Assembly > Xceed.Wpf.DataGrid.Converters Namespace : StatResultConverter Class

Represents a converter that can be used to format the result of a statistical function, as well as display a user-friendly message when an exception occurs within the function during the calculation of its result. This feature is available only in the Professional Edition

Syntax

Visual Basic (Declaration) 
Public Class StatResultConverter 
   Inherits StringFormatConverter
   Implements IValueConverter 
C# 
public class StatResultConverter : StringFormatConverter, IValueConverter 

Example

All examples in this topic assume that the grid is bound to the Orders or Employees tables of the Northwind database, unless stated otherwise.
The following example demonstrates how to display the results of various statistical functions in and outside of a grid.
XAMLCopy Code
<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"> 
  <Grid.Resources> 
    <xcdg:DataGridCollectionViewSource x:Key="cvs_orderdetails" 
                                       Source="{Binding Source={x:Static Application.Current}, 
                                                        Path=OrderDetails}"> 
     <xcdg:DataGridCollectionViewSource.StatFunctions> 
       <xcdg:CountFunction ResultPropertyName="orderid_count" 
                           SourcePropertyName="OrderID"/> 
       <xcdg:SumFunction ResultPropertyName="unitprice_sum" 
                         SourcePropertyName="UnitPrice"/> 
       <xcdg:AverageFunction ResultPropertyName="unitprice_average" 
                             SourcePropertyName="UnitPrice"/> 
       <xcdg:SumFunction ResultPropertyName="quantity_sum" SourcePropertyName="Quantity"/> 
     </xcdg:DataGridCollectionViewSource.StatFunctions> 
     <xcdg:DataGridCollectionViewSource.GroupDescriptions> 
       <xcdg:DataGridGroupDescription PropertyName="ProductID"/>       
 </xcdg:DataGridCollectionViewSource.GroupDescriptions> 
    </xcdg:DataGridCollectionViewSource> 
   <xcdg:StatResultConverter x:Key="valueConverter"/> 
  </Grid.Resources> 
  <DockPanel> 
    <StackPanel Orientation="Horizontal" DockPanel.Dock="Top"> 
      <TextBlock Text="Total Orders: "/> 
      <TextBlock Text="{Binding ElementName=OrderDetailsGrid, 
                 Path=StatContext.orderid_count}"/> 
    </StackPanel> 
     <StackPanel Orientation="Horizontal" DockPanel.Dock="Top"> 
       <TextBlock Text="Average Unit Price: "/> 
     <TextBlock Text="{Binding ElementName=OrderDetailsGrid, 
                        Path=StatContext.unitprice_average, 
                        Converter={StaticResource valueConverter}, 
                        ConverterParameter=f2}"/> 
    </StackPanel> 
    <xcdg:DataGridControl x:Name="OrderDetailsGrid" 
                          ItemsSource="{Binding Source={StaticResource cvs_orderdetails}}" 
                          DockPanel.Dock="Bottom"> 
      <xcdg:DataGridControl.DefaultGroupConfiguration> 
        <xcdg:GroupConfiguration>  
        <xcdg:GroupConfiguration.Footers> 
           <DataTemplate> 
               <xcdg:StatRow> 
               <xcdg:StatCell FieldName="UnitPrice" 
                                   ResultPropertyName="unitprice_sum"/> 
               <xcdg:StatCell FieldName="Quantity" ResultPropertyName="quantity_sum"/> 
               <xcdg:StatCell FieldName="OrderID" ResultPropertyName="orderid_count"/> 
               <xcdg:StatCell FieldName="UnitPrice" 
                              ResultPropertyName="unitprice_average" 
                              ResultConverterParameter="f2"/> 
             </xcdg:StatRow> 
           </DataTemplate> 
         </xcdg:GroupConfiguration.Footers> 
        </xcdg:GroupConfiguration> 
      </xcdg:DataGridControl.DefaultGroupConfiguration>     
    </xcdg:DataGridControl> 
  </DockPanel> 
</Grid>
The following example demonstrates how to change the statistical context of a TextBlock that displays the results of a statistical function when the current item is changed. The statistical context of the TextBlock will be changed in the grid's PropertyChanged event handler by using the GetParentGroupFromItem method to retrieve the current group and set it as the new statistical context. To simplify the code below, the DataContext of the StackPanel could have been modified rather than the DataContext of each TextBlock. The implementation of the PropertyChanged event handler is located below.
XAMLCopy Code
<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"> 
  <Grid.Resources> 
    <xcdg:DataGridCollectionViewSource x:Key="cvs_orderdetails" 
                                    Source="{Binding Source={x:Static Application.Current},  
                                                     Path=OrderDetails}"> 
 
      <xcdg:DataGridCollectionViewSource.StatFunctions> 
        <xcdg:CountFunction ResultPropertyName="orderid_count" 
                            SourcePropertyName="OrderID"/> 
        <xcdg:AverageFunction ResultPropertyName="unitprice_average" 
                              SourcePropertyName="UnitPrice"/>               
      </xcdg:DataGridCollectionViewSource.StatFunctions> 
      <xcdg:DataGridCollectionViewSource.GroupDescriptions> 
        <xcdg:DataGridGroupDescription PropertyName="ProductID"/> 
      </xcdg:DataGridCollectionViewSource.GroupDescriptions> 
    </xcdg:DataGridCollectionViewSource> 
    <xcdg:StatResultConverter x:Key="valueConverter"/> 
  </Grid.Resources> 
  <DockPanel> 
    <StackPanel Orientation="Horizontal" DockPanel.Dock="Top"> 
      <TextBlock Text="Results for product "/> 
      <TextBlock x:Name="CurrentGroupTitle" Text="{Binding Name}"/> 
      <TextBlock Text=": "/> 
      <TextBlock Text="     Total Orders-"/> 
      <TextBlock x:Name="TotalOrders" Text="{Binding orderid_count}"/> 
      <TextBlock Text="     Average Unit Price-"/> 
      <TextBlock x:Name="AveragePrice" 
                 Text="{Binding unitprice_average, 
                        Converter={StaticResource valueConverter}, 
                        ConverterParameter=f2}"/> 
    </StackPanel> 
    <xcdg:DataGridControl x:Name="OrderDetailsGrid" 
                          ItemsSource="{Binding Source={StaticResource cvs_orderdetails}}" 
                          PropertyChanged="CurrentItemChanged" 
                          DockPanel.Dock="Bottom"/> 
  </DockPanel> 
</Grid>
The following code provides the implementation of the PropertyChanged event handler.
Visual BasicCopy Code
Private Sub CurrentItemChanged( ByVal sender As Object, _
                                ByVal e AsPropertyChangedEventArgs )
  If e.PropertyName = "CurrentItem" Then

    If Me.OrderDetailsGrid.CurrentItem Is Nothing Then
      Return

    Dim group As CollectionViewGroup =
              Me.OrderDetailsGrid.GetParentGroupFromItem( Me.OrderDetailsGrid.CurrentItem )

    Me.CurrentGroupTitle.DataContext = group
    Me.TotalOrders.DataContext = group
    Me.AveragePrice.DataContext = group
  End If
End Sub
The following code provides the implementation of the PropertyChanged event handler.
C#Copy Code
private void CurrentItemChanged( object sender, PropertyChangedEventArgs e )
{
 if( e.PropertyName == "CurrentItem" )
 {

   if( this.OrderDetailsGrid.CurrentItem == null )
     return;

   CollectionViewGroup group =
             this.OrderDetailsGrid.GetParentGroupFromItem( this.OrderDetailsGrid.CurrentItem );

   this.CurrentGroupTitle.DataContext = group;
   this.TotalOrders.DataContext = group;
   this.AveragePrice.DataContext = group;
 }
}
The following example demonstrates how to create a custom data template that will be used in the footers of the first-level groups to display the results of various statistical functions.
XAMLCopy Code
<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"> 
  <Grid.Resources> 
    <xcdg:DataGridCollectionViewSource x:Key="cvs_orderdetails" 
                                       Source="{Binding Source={x:Static Application.Current}, 
                                                        Path=OrderDetails}">  
    <xcdg:DataGridCollectionViewSource.StatFunctions> 
       <xcdg:CountFunction ResultPropertyName="orderid_count" 
                           SourcePropertyName="OrderID"/> 
       <xcdg:SumFunction ResultPropertyName="unitprice_sum" 
                         SourcePropertyName="UnitPrice"/> 
       <xcdg:AverageFunction ResultPropertyName="unitprice_average" 
                             SourcePropertyName="UnitPrice"/> 
       <xcdg:SumFunction ResultPropertyName="quantity_sum" 
                         SourcePropertyName="Quantity"/> 
     </xcdg:DataGridCollectionViewSource.StatFunctions>        
      <xcdg:DataGridCollectionViewSource.GroupDescriptions> 
        <xcdg:DataGridGroupDescription PropertyName="ProductID"/> 
      </xcdg:DataGridCollectionViewSource.GroupDescriptions> 
    </xcdg:DataGridCollectionViewSource> 
   <xcdg:StatResultConverter x:Key="valueConverter"/> 
  </Grid.Resources> 
  <xcdg:DataGridControl x:Name="OrderDetailsGrid" 
                        ItemsSource="{Binding Source={StaticResource cvs_orderdetails}}"> 
    <xcdg:DataGridControl.DefaultGroupConfiguration> 
      <xcdg:GroupConfiguration> 
        <xcdg:GroupConfiguration.Footers> 
          <xcdg:GroupHeaderFooterItemTemplate VisibleWhenCollapsed="True"> 
            <DataTemplate> 
              <Border Background="#999999" 
                      BorderBrush="LightBlue" 
                      BorderThickness="3" 
                      Margin="5" > 
                <Grid> 
                  <Grid.ColumnDefinitions> 
                    <ColumnDefinition/> 
                    <ColumnDefinition/> 
                  </Grid.ColumnDefinitions> 
                  <Grid.RowDefinitions> 
                    <RowDefinition/> 
                    <RowDefinition/> 
                    <RowDefinition/> 
                    <RowDefinition/> 
                  </Grid.RowDefinitions> 
                  <TextBlock Text="Total Orders: " Grid.Row="0" Grid.Column="0"/> 
                   <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, 
                                             Path=(xcdg:DataGridControl.StatContext).orderid_count}" 
                              Grid.Row="0" Grid.Column="1"/>                     
                    <TextBlock Text="Total Quantity Sold: " Grid.Row="1" Grid.Column="0"/> 
                   <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, 
                                   Path=(xcdg:DataGridControl.StatContext).quantity_sum}" 
                                   Grid.Row="1" Grid.Column="1"/>   
                    <TextBlock Text="Total Sales: " Grid.Row="2" Grid.Column="0"/> 
                   <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, 
                                             Path=(xcdg:DataGridControl.StatContext).unitprice_sum}" 
                              Grid.Row="2" Grid.Column="1"/>   
                    <TextBlock Text="Average Unit Price: " Grid.Row="3" Grid.Column="0"/> 
                   <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, 
                                             Path=(xcdg:DataGridControl.StatContext).unitprice_average, 
                                             Converter={StaticResource valueConverter}, 
                                             ConverterParameter=f2}" 
                              Grid.Row="3" Grid.Column="1"/>          
                  </Grid> 
                </Border>  
              </DataTemplate>   
            </xcdg:GroupHeaderFooterItemTemplate> 
          </xcdg:GroupConfiguration.Footers> 
        </xcdg:GroupConfiguration> 
      </xcdg:DataGridControl.DefaultGroupConfiguration> 
      <xcdg:DataGridControl.View> 
        <xcdg:CardView AllowCardResize="True"/> 
      </xcdg:DataGridControl.View> 
    </xcdg:DataGridControl> 
  </Grid>
The following example demonstrates how to explicitly define detail descriptions for the DataRelations found in the DataTable to which the grid is bound and how to calculate statistical functions for a detail description whose results will be displayed in the StatRows contained in the footer sections of the details to which the description's corresponding detail configuration will be applied.
XAMLCopy Code
<Grid> 
  <Grid.Resources> 
     <xcdg:DataGridCollectionViewSource x:Key="cvs_employees" 
                                        Source="{Binding Source={x:Static Application.Current},  
                                                         Path=Employees}"> 
 
       <xcdg:DataGridCollectionViewSource.DetailDescriptions> 
          <xcdg:DataRelationDetailDescription RelationName="Employee_Orders" 
                                              Title="Employee Orders"> 
             <xcdg:DataRelationDetailDescription.DetailDescriptions> 
                <xcdg:DataRelationDetailDescription RelationName="Order_OrderDetails" 
                                                    Title="Order Details"> 
                   <xcdg:DataRelationDetailDescription.ItemProperties> 
                      <xcdg:DataGridItemProperty Name="UnitPrice" /> 
                      <xcdg:DataGridItemProperty Name="Quantity" /> 
                      <xcdg:DataGridItemProperty Name="Discount" /> 
                   </xcdg:DataRelationDetailDescription.ItemProperties> 
                   <xcdg:DataRelationDetailDescription.StatFunctions>                           
                      <xcdg:SumFunction ResultPropertyName="sum_quantity" 
                                        SourcePropertyName="Quantity" /> 
                      <xcdg:AverageFunction ResultPropertyName="average_unitprice" 
                                            SourcePropertyName="UnitPrice" /> 
                   </xcdg:DataRelationDetailDescription.StatFunctions> 
                </xcdg:DataRelationDetailDescription> 
             </xcdg:DataRelationDetailDescription.DetailDescriptions> 
          </xcdg:DataRelationDetailDescription> 
       </xcdg:DataGridCollectionViewSource.DetailDescriptions> 
     </xcdg:DataGridCollectionViewSource> 
  </Grid.Resources> 
  
  <xcdg:DataGridControl x:Name="EmployeesGrid" 
                      ItemsSource="{Binding Source={StaticResource cvs_employees}}" 
                      ItemsSourceName="Employee Information" 
                      AutoCreateDetailConfigurations="True"> 
 
    <xcdg:DataGridControl.DetailConfigurations> 
       <xcdg:DetailConfiguration RelationName="Employee_Orders"> 
          <xcdg:DetailConfiguration.DetailConfigurations> 
             <xcdg:DetailConfiguration RelationName="Order_OrderDetails"> 
                <xcdg:DetailConfiguration.Footers> 
                   <DataTemplate> 
                      <xcdg:StatRow Background="AliceBlue"> 
                         <xcdg:StatCell FieldName="UnitPrice" 
                                        ResultPropertyName="average_unitprice" 
                                        ResultConverterParameter="f2" /> 
                         <xcdg:StatCell FieldName="Quantity" 
                                        ResultPropertyName="sum_quantity" />                              
                      </xcdg:StatRow> 
                   </DataTemplate> 
                </xcdg:DetailConfiguration.Footers> 
             </xcdg:DetailConfiguration> 
          </xcdg:DetailConfiguration.DetailConfigurations> 
       </xcdg:DetailConfiguration> 
     </xcdg:DataGridControl.DetailConfigurations>   
   </xcdg:DataGridControl> 
</Grid>

Remarks

The messages returned by a StatResultConverter when an exception occurs during the calculation of a statistical function's result depend on the type of the exception that was thrown. The following table provides a list of exceptions for which default messages have been provided: 

Exception Default message
DivideByZeroException #DIV/0#
Exception #[Exception.Message]#
InvalidSourcePropertyNameException #[InvalidSourcePropertyNameException.SourcePropertyName]#
InvalidValueException #VALUE#
OverflowException #OVER#

Composite format strings use braces ("{}") to identify place-holders, which causes an issue when providing a format string to a StatResultConverter in XAML; therefore, the StatResultConverter supports square brackets ("[]") as a substitute for braces. For example, if normally {0:#0.0} would have been used, it would be replaced with [#0.0] when using a StatResultConverter. If braces are preferred, the format string must be preceded with a closing brace (e.g., ConverterParameter={}{0:#0.0}}).

When using square brackets, the 0: that represents the place-holder must be omitted otherwise an exception will be thrown.

Inheritance Hierarchy

System.Object
   Xceed.Wpf.DataGrid.Converters.StringFormatConverter
      Xceed.Wpf.DataGrid.Converters.StatResultConverter

Requirements

Supported Operating Systems: Windows Server 2003 Service Pack 1; Windows Vista; Windows XP Service Pack 2

See Also