Xceed DataGrid for WPF v7.2 Documentation
Detail Descriptions

Welcome to Xceed DataGrid, Editors, and 3D Views for WPF v7.2 > Xceed DataGrid for WPF > DataGrid Fundamentals > Manipulating Data > Providing, Inserting, and Removing Data > Master/Detail > Detail Descriptions

Prerequisite Knowledge
DataGrid Fundamentals: Object Model Overview
DataGrid Fundamentals: DataGridCollectionView Class

The DataGridDetailDescription class provides information about a detail relation whose content will be displayed as the details of the data items in a grid or another detail. By default, detail descriptions are automatically created for:

Detail descriptions can also be explicitly defined by adding them to DetailDescriptions collection of their parent DataGridCollectionView,  DataGridCollectionViewSource, or detail description.

Every detail description must have a unique, identifying relation name that can be provided through its RelationName property and that will be used by detail configurations to identify which description their configuration will be applied to. If the detail descriptions are automatically created, their relation name will be extracted from the underlying detail source or a default one will be provided. If they are explicitly provided, then their relation name must also be explicitly set.

Automatic creation of detail descriptions can be disabled by setting the AutoCreateDetailDescriptions property of the DataGridCollectionViewSource to false (by default, true) or by specifying so when creating an instance of the DataGridCollectionView. 

For each property in the corresponding detail description's source, a DataGridItemProperty will be created and added to its ItemProperties collection (you can consider these items to be the columns that will end up in the details). Each item-property object represents the characteristics of a property for an item in the detail description, including the DataType, Name, PropertyDescriptor, Title, and ValuePath. Automatic creation of item properties can be disabled by setting the AutoCreateItemProperties property of the DataGridCollectionViewSource to false (by default, true) or by specifying so when creating an instance of the DataGridCollectionView.

Entity Framework

By default the Entity Framework does not load references to related entity objects. In this situation, the QueryDetails event exposed by the EntityDetailDescription class can be handled to provide details for a data item. For example, in the code snippet below, a query that will return the appropriate details for a parent item is executed and the Handled property set to true to indicate that the event was handled. In the case where the event is not handled and columns contain references to external Entity objects, the column would have remained empty unless those objects had been cached when loaded by some other means.

VB.NET
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Private Sub EntityDetailDescription_QueryDetails( sender As Object, e As QueryEntityDetailsEventArgs )
  Dim customer As Customer = TryCast( e.ParentItem, Customer )
  ' Since EntityFramework doesn't load automatically references to
  ' other objects, we build a query that will include those objects.
  ' We start from the base query but we could have added restrictions
  ' to the query.
  Dim query As ObjectQuery( Of Order ) = customer.Orders.CreateSourceQuery()
  customer.Orders.Attach( query.Include( "Employee" ).Include( "Shipper" ) )
  e.Handled = True
End Sub
C#
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private void EntityDetailDescription_QueryDetails( object sender, QueryEntityDetailsEventArgs e )
{
 Customer customer = ( Customer )e.ParentItem;
 // Since EntityFramework doesn't load automatically references to
 // other objects, we build a query that will include those objects.
 // We start from the base query but we could have added restrictions
 // to the query.
 ObjectQuery<Order> query = customer.Orders.CreateSourceQuery();
 customer.Orders.Attach( query.Include( "Employee" ).Include( "Shipper" ) );
 e.Handled = true;
}

Because an Entity object does not have a default visual representation, its string representation will be displayed in the column. In order to change its appearance, a CellContentTemplate must be provided.

Grouping, Sorting, and Filtering

Data items contained in a detail can be grouped using either the default PropertyGroupDescription or the DataGridGroupDescription (recommended) and adding them to the GroupDescriptions property of the corresponding detail description. Data items can also be sorted by adding the standard SortDescription structures to the SortDescriptions property.

The data items that are to be displayed in a detail can be filtered through automatic filtering, which provides Excel-like end-user filtering according to the distinct values of each column (see Filtering Data).  

For more information on grouping, sorting, and filtering data items, refer to the Grouping Data, Sorting Data and Filtering Data topics.

Examples

All examples in this topic assume that the grid is bound to the Employees table of the Northwind database, unless stated otherwise.

Example 1: Defining detail descriptions

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.

XAML
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<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>

Example 2: Creating a custom detail description

The following example demonstrates how to create and use a custom detail description that handles LINQ detail relations, which are provided by properties to which the AssociationAttribute is applied.

VB.NET
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Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports Xceed.Wpf.DataGrid
Imports System.Reflection
Imports System.Data.Linq.Mapping
Imports System.Diagnostics
Imports System.Collections
Namespace Xceed.Wpf.Documentation
  Public Class LinqToSqlDetailDescription
               Inherits DataGridDetailDescription
    Protected Overrides Function GetDetailsForParentItem( ByVal parentCollectionView As DataGridCollectionView, _
                                                          ByVal parentItem As Object ) As IEnumerable
      Dim parentItemType As Type = parentItem.GetType()
      Dim foundProperty As PropertyInfo = Nothing
      Dim properties() As PropertyInfo = parentItemType.GetProperties()
      Dim propertyInfo As PropertyInfo
      For Each propertyInfo In properties
        Dim attributes() As Object = propertyInfo.GetCustomAttributes( Type.GetType( AssociationAttribute ), _
                                                                        False)
        If attributes.GetLength( 0 ) = 0 Then
          continue
        End If
        Dim associationAttribute As AssociationAttribute = CType( attributes( 0 ), AssociationAttribute )
        If associationAttribute.Name = Me.RelationName Then
          foundProperty = propertyInfo
          Exit Property
        End If
      Next
      If foundProperty Is Nothing Then
        Return New Object()
      Else
        Dim details As Object = foundProperty.GetValue( parentItem, Nothing )
        Dim detailsType As Type = details.GetType()
        Dim getNewBindingList As MethodInfo = detailsType.GetMethod( "GetNewBindingList" )
        Return CType( getNewBindingList.Invoke( details, Nothing), IEnumerable )
      End If
    End Function
  End Class
End Namespace
C#
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xceed.Wpf.DataGrid;
using System.Reflection;
using System.Data.Linq.Mapping;
using System.Diagnostics;
using System.Collections;
namespace Xceed.Wpf.Documentation
{
 public class LinqToSqlDetailDescription: DataGridDetailDescription
 {
   protected override IEnumerable GetDetailsForParentItem( DataGridCollectionView parentCollectionView,
                                                           object parentItem )
   {
     Type parentItemType = parentItem.GetType();
     PropertyInfo foundProperty = null;
    
     PropertyInfo[] properties = parentItemType.GetProperties();
     foreach( PropertyInfo propertyInfo in properties )
     {
       object[] attributes = propertyInfo.GetCustomAttributes( typeof( AssociationAttribute ), false );
       if( attributes.GetLength( 0 ) == 0 )
         continue;
       AssociationAttribute associationAttribute = ( AssociationAttribute )attributes[ 0 ];
       if( associationAttribute.Name == this.RelationName )
       {
         foundProperty = propertyInfo;
         break;
       }
     }
     if( foundProperty == null )
     {
       return new object[] { };
     }
     else
     {
       object details = foundProperty.GetValue( parentItem, null );
       Type detailsType = details.GetType();
       MethodInfo getNewBindingList = detailsType.GetMethod( "GetNewBindingList" );
       return ( IEnumerable )getNewBindingList.Invoke( details, null );
     }
   }
 }
}
XAML
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<Grid>
  <Grid.Resources>
    <xcdg:DataGridCollectionViewSource x:Key="cvs_employees"
                                       Source="{Binding Source={x:Static Application.Current},
                                                        Path=LinqDataContext.Employees}">
       <xcdg:DataGridCollectionViewSource.DetailDescriptions>
          <local:LinqToSqlDetailDescription RelationName="Employee_Employees"
                                            Title="Employees" />
          <local:LinqToSqlDetailDescription RelationName="Employee_Customer"
                                            Title="Customers">
             <local:LinqToSqlDetailDescription.DetailDescriptions>
                <local:LinqToSqlDetailDescription RelationName="Customer_Order"
                                                  Title="Orders">
                   <local:LinqToSqlDetailDescription.DetailDescriptions>
                      <local:LinqToSqlDetailDescription RelationName="Order_Order_Detail"
                                                        Title="Order Details" />
                   </local:LinqToSqlDetailDescription.DetailDescriptions>
                </local:LinqToSqlDetailDescription>
             </local:LinqToSqlDetailDescription.DetailDescriptions>
          </local:LinqToSqlDetailDescription>
       </xcdg:DataGridCollectionViewSource.DetailDescriptions>
    </xcdg:DataGridCollectionViewSource>
  </Grid.Resources>
 
  <xcdg:DataGridControl x:Name="EmployeesGrid"
                      ItemsSource="{Binding Source={StaticResource cvs_employees}}"
                      ItemsSourceName="Employee Information"
                      AutoCreateDetailConfigurations="True" />
</Grid>
VB.NET
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Dim context As New NorthwindDataContext()
Dim collectionView As New DataGridCollectionView( context.Employees, GetType( Employee ), True, False )
collectionView.DetailDescriptions.Add( New LinqToSqlDetailDescription( "Employee_Employees", "Employees" ) )
Dim employeeCustomerDetail As New LinqToSqlDetailDescription( "Employee_Customer", "Customers" )
Dim customerOrderDetail As New LinqToSqlDetailDescription( "Customer_Order", "Orders" )
customerOrderDetail.DetailDescriptions.Add( New LinqToSqlDetailDescription( "Order_Order_Detail", "Order Details" ) )
employeeCustomerDetail.DetailDescriptions.Add( customerOrderDetail )
collectionView.DetailDescriptions.Add( employeeCustomerDetail )
dataGridControl.AutoCreateDetailConfigurations = True
dataGridControl.ItemsSourceName = "Employee Information"
dataGridControl.ItemsSource = collectionView
C#
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NorthwindDataContext context = new NorthwindDataContext();      
DataGridCollectionView collectionView = new DataGridCollectionView( context.Employees, typeof( Employee ), true, false );      
collectionView.DetailDescriptions.Add( new LinqToSqlDetailDescription( "Employee_Employees", "Employees" ) );
LinqToSqlDetailDescription employeeCustomerDetail = new LinqToSqlDetailDescription( "Employee_Customer", "Customers" );
LinqToSqlDetailDescription customerOrderDetail = new LinqToSqlDetailDescription( "Customer_Order", "Orders" );
customerOrderDetail.DetailDescriptions.Add( new LinqToSqlDetailDescription( "Order_Order_Detail", "Order Details" ) );
employeeCustomerDetail.DetailDescriptions.Add( customerOrderDetail );
collectionView.DetailDescriptions.Add( employeeCustomerDetail );
dataGridControl.AutoCreateDetailConfigurations = true;
dataGridControl.ItemsSourceName = "Employee Information";
dataGridControl.ItemsSource = collectionView;

 

 

 

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