Sorting Data Items

The following page provides a list of examples that demonstrate how to sort data items.

note

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

Sorting data items

The following example demonstrates how to sort the data items in an ascending direction according to the values of the ShipCountry column.

XAML

  <Grid xmlns:scm="clr-namespace:System.ComponentModel;assembly=WindowsBase"
        xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid">
    <Grid.Resources>
      <xcdg:DataGridCollectionViewSource x:Key="cvs_orders"
                                      Source="{Binding Source={x:Static Application.Current},
                                                        Path=Orders}">
      <xcdg:DataGridCollectionViewSource.SortDescriptions>
        <scm:SortDescription PropertyName="ShipCountry" Direction="Ascending"/>
      </xcdg:DataGridCollectionViewSource.SortDescriptions>
      </xcdg:DataGridCollectionViewSource>          
    </Grid.Resources>
    <xcdg:DataGridControl x:Name="OrdersGrid"
                          ItemsSource="{Binding Source={StaticResource cvs_orders}}">
      <xcdg:DataGridControl.Columns>
        <xcdg:Column FieldName="ShipCountry" VisiblePosition="0"/>
      </xcdg:DataGridControl.Columns>
    </xcdg:DataGridControl>
  </Grid>

C#

DataGridCollectionView collectionView = new DataGridCollectionView( Orders );
collectionView.SortDescriptions.Add( new SortDescription( "ShipCountry", ListSortDirection.Ascending ) );
dataGridControl.ItemsSource = collectionView;
dataGridControl.Columns[ "ShipCountry" ].VisiblePosition = 0;

VB.NET

Dim collectionView As New DataGridCollectionView( Orders )
collectionView.SortDescriptions.Add( New SortDescription( "ShipCountry", ListSortDirection.Ascending ) )
dataGridControl.ItemsSource = collectionView
dataGridControl.Columns( "ShipCountry" ).VisiblePosition = 0

Preventing sorting and grouping

The following example demonstrates how to bind a grid to the Orders table and prevent columns from being sorted and reordered and groups from being created or removed. By default, the ShipCountry and ShipCity columns will be sorted, grouped, and fixed.

XAML

  <Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"
        xmlns:d="clr-namespace:System.Windows.Data;assembly=PresentationFramework"
        xmlns:scm="clr-namespace:System.ComponentModel;assembly=WindowsBase">
    <Grid.Resources>
      <xcdg:DataGridCollectionViewSource x:Key="cvs_orders"
                                      Source="{Binding Source={x:Static Application.Current},
                                                        Path=Orders}">
        <xcdg:DataGridCollectionViewSource.SortDescriptions>
          <scm:SortDescription PropertyName="ShipCountry" Direction="Ascending"/>
          <scm:SortDescription PropertyName="ShipCity" Direction="Ascending"/>
        </xcdg:DataGridCollectionViewSource.SortDescriptions>
        <xcdg:DataGridCollectionViewSource.GroupDescriptions>
          <xcdg:DataGridGroupDescription PropertyName="ShipCountry"/>
          <xcdg:DataGridGroupDescription PropertyName="ShipCity"/>
        </xcdg:DataGridCollectionViewSource.GroupDescriptions>
      </xcdg:DataGridCollectionViewSource>
    </Grid.Resources>
    <xcdg:DataGridControl x:Name="OrdersGrid"
                          ItemsSource="{Binding Source={StaticResource cvs_orders}}">      
      <xcdg:DataGridControl.Columns>
        <xcdg:Column FieldName="ShipCountry" VisiblePosition="0"/>
        <xcdg:Column FieldName="ShipCity" VisiblePosition="1"/>
      </xcdg:DataGridControl.Columns>
      <xcdg:DataGridControl.View>
        <xcdg:TableView FixedColumnCount="2" UseDefaultHeadersFooters="False">
          <xcdg:TableView.FixedHeaders>
            <DataTemplate>
              <xcdg:GroupByControl AllowSort="False" AllowGroupingModification="False"/>
            </DataTemplate>
            <DataTemplate>
              <xcdg:ColumnManagerRow AllowSort="False" AllowColumnReorder="False"/>
            </DataTemplate>
          </xcdg:TableView.FixedHeaders>
        </xcdg:TableView>
      </xcdg:DataGridControl.View>
    </xcdg:DataGridControl>
  </Grid>

Custom sorting

This example demonstrates how to create a custom group description by deriving from the DataGridGroupDescription class and overriding the GroupNameFromItem method. The custom group description will group items according to the first letter in the value received as a parameter. The example results in the group being present at initial loading; also, when removing and re-adding the group, the custom group description is not triggered. See below for an alternative approach to avoid this.

The implementation for the custom sort comparer assigned to the group description's SortComparer property is provided below.

C#

  using System;
  using System.Collections.Generic;
  using System.Text;
  using Xceed.Wpf.DataGrid;
  using System.Collections;
  namespace Xceed.Wpf.Documentation
  {
    public class AlphabeticalGroupDescription : DataGridGroupDescription
    {
      public AlphabeticalGroupDescription()
        : base()
      {
      }
      public AlphabeticalGroupDescription( string propertyName )
        : base( propertyName )
      {
      }
    
      public override object GroupNameFromItem( object item, int level,
                                                System.Globalization.CultureInfo culture )
      {
        object value = base.GroupNameFromItem( item, level, culture );
        try
        {
          string content = Convert.ToString( value );
          value = content.ToUpper().Substring( 0, 1 );
        }
        catch( InvalidCastException )
        {
        }
        return value;
      }
    }
  }

VB.NET

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Xceed.Wpf.DataGrid
Imports System.Collections
Imports System.Globalization;
Namespace Xceed.Wpf.Documentation
  Public Class AlphabeticalGroupDescription
        Inherits DataGridGroupDescription
    Public Sub New()
      MyBase.New()
    End Sub
    Public Sub New(ByVal propertyName As String)
    MyBase.New(propertyName)
    End Sub
    Public Overrides Function GroupNameFromItem(ByVal item As Object, _
                                                ByVal level As Integer, _
                                                ByVal culture As CultureInfo) As Object
      Dim value As Object = MyBase.GroupNameFromItem(item, level, culture)
      Try
        Dim content As String = Convert.ToString(value)
        value = content.ToUpper().Substring(0, 1)
      Catch e1 As InvalidCastException
      End Try
      Return value
    End Function
  End Class
End Namespace

The following code demonstrates how to use the custom group description by adding it to the DataGridCollectionViewSource's GroupDescriptions property.

XAML

<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"
    xmlns:local="clr-namespace:Xceed.Wpf.Documentation">
  <Grid.Resources>     
    <local:ConsonantVowelComparer x:Key="consonantVowelComparer"/>
    <xcdg:DataGridCollectionViewSource x:Key="cvs_orders"
                                      Source="{Binding
                                                Source={x:Static Application.Current},
                                                Path=Orders}">
    <xcdg:DataGridCollectionViewSource.GroupDescriptions>
      <local:AlphabeticalGroupDescription PropertyName="ShipCountry"
                                SortComparer="{StaticResource consonantVowelComparer}"/>
    </xcdg:DataGridCollectionViewSource.GroupDescriptions>
    </xcdg:DataGridCollectionViewSource>
  </Grid.Resources>
  <xcdg:DataGridControl x:Name="OrdersGrid"
                        ItemsSource="{Binding Source={StaticResource cvs_orders}}"/>
</Grid>

C#

DataGridCollectionView collectionView = new DataGridCollectionView( Orders );
AlphabeticalGroupDescription groupDescription = new AlphabeticalGroupDescription( "ShipCountry" );
groupDescription.SortComparer = new ConsonantVowelComparer();
collectionView.GroupDescriptions.Add( groupDescription );
dataGridControl.ItemsSource = collectionView;

VB.NET

Dim collectionView As New DataGridCollectionView( Orders )
Dim groupDescription As New AlphabeticalGroupDescription( "ShipCountry" )
groupDescription.SortComparer = New ConsonantVowelComparer()
collectionView.GroupDescriptions.Add( groupDescription )
dataGridControl.ItemsSource = collectionView

The following code provides the implementation for the custom sort comparer that is used to sort, by vowels then consonants, the group descriptions create above.

XAML

  <Window.Resources>
      <local:DateGroupDescription x:Key="myDateGroupDescription"
                                  PropertyName="DateTimeFieldName" />
  </Window.Resources>

  [...]

  <xcdg:DataGridControl.Columns>
    <xcdg:Column FieldName="DateTimeFieldName"
                GroupDescription="{StaticResource myDateGroupDescription}" />
  </xcdg:DataGridControl.Columns>

C#

  using System;
  using System.Collections.Generic;
  using System.Text;
  using System.Collections;
  namespace Xceed.Wpf.Documentation
  {
    public class ConsonantVowelComparer : IComparer
    {
      public ConsonantVowelComparer()
      {
      }
      public int Compare( object x, object y )
      {
        if( ( x is string ) && ( y is string ) )
        {
          string xString = x.ToString().ToLowerInvariant();
          string yString = y.ToString().ToLowerInvariant();
          bool isXVowel = m_vowels.Contains( xString );
          bool isYVowel = m_vowels.Contains( yString );
          if( isXVowel ^ isYVowel )
            return isXVowel ? -1 : 1;
          return String.Compare( xString, yString );      
        }
        throw new ArgumentException();
      }
      private const string m_vowels = "aeiouy";
    }
  }

VB.NET

  Imports System
  Imports System.Collections.Generic
  Imports System.Text
  Imports System.Collections
  Namespace Xceed.Wpf.Documentation
    Public Class ConsonantVowelComparer
      Implements IComparer
      Public Sub New()
      End Sub

      Public Function Compare(ByVal x As Object, _
                              ByVal y As Object) As Integer Implements IComparer.Compare
        If (TypeOf x Is String) AndAlso (TypeOf y Is String) Then
          Dim xString As String = x.ToString().ToLowerInvariant()
          Dim yString As String = y.ToString().ToLowerInvariant()
          Dim isXVowel As Boolean = m_vowels.Contains(xString)
          Dim isYVowel As Boolean = m_vowels.Contains(yString)
          If isXVowel Xor isYVowel Then
            If isXVowel Then
              Return -1
            Else
              Return 1
            End If
          End If
          Return String.Compare(xString, yString)
        End If
        Throw New ArgumentException()
      End Function
      Private Const m_vowels As String = "aeiouy"
    End Class
  End Namespace

Handling collection-changed events

The following example demonstrates how to subscribe to the CollectionChanged event of the DataGridCollectionView.SortDescriptions collection's INotifyCollectionChanged interface implementation to be notified when sorting applied to a grid's columns changes.

C#

  protected override void OnInitialized( EventArgs e )
  {
    base.OnInitialized( e ); 
    DataGridCollectionView view = this.OrdersGrid.ItemsSource as DataGridCollectionView;
    ( ( INotifyCollectionChanged )view.SortDescriptions ).CollectionChanged +=
                                        new NotifyCollectionChangedEventHandler( this.SortCollectionChanged );
  } 
  private void SortCollectionChanged( object sender, NotifyCollectionChangedEventArgs e )
  {
    Debug.WriteLine( "Sort changed" );
  }

VB.NET

Protected Overrides Sub OnInitialized(ByVal e As EventArgs)
  MyBase.OnInitialized(e)

  Dim view As DataGridCollectionView = TryCast(Me.OrdersGrid.ItemsSource, DataGridCollectionView)
  AddHandler (CType(view.SortDescriptions, INotifyCollectionChanged)).CollectionChanged,
                                          AddressOf SortCollectionChanged
End Sub
Private Sub SortCollectionChanged(ByVal sender As Object, ByVal e As NotifyCollectionChangedEventArgs)
  Debug.WriteLine("Sort changed")
End Sub

Providing a custom sort comparer

The following example demonstrates how to provide a custom sort comparer that sorts addresses. The AddressComparer class (provided below) will first sort addresses which begin with numeric values by street name and then civic number. Address that do not have a civic number will be sorted alphabetically.

XAML

  <Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"
        xmlns:local="clr-namespace:Xceed.Wpf.Documentation">
    <Grid.Resources>
        <local:AddressComparer x:Key="addressComparer"/>
        <xcdg:DataGridCollectionViewSource x:Key="cvs_orders"
                                          Source="{Binding Source={x:Static Application.Current},
                                                            Path=Orders}"
                                          AutoCreateItemProperties="False">
          <xcdg:DataGridCollectionViewSource.ItemProperties>
              <xcdg:DataGridItemProperty Name="ShipCountry" />
              <xcdg:DataGridItemProperty Name="ShipCity" />
              <xcdg:DataGridItemProperty Name="ShipAddress"
                                        SortComparer="{StaticResource addressComparer}"/>
              <xcdg:DataGridItemProperty Name="ShipVia" />
          </xcdg:DataGridCollectionViewSource.ItemProperties>
        </xcdg:DataGridCollectionViewSource>
    </Grid.Resources>
    <xcdg:DataGridControl x:Name="OrdersGrid"
                          ItemsSource="{Binding Source={StaticResource cvs_orders}}"/>         
  </Grid>

C#

  DataGridCollectionView collectionView = new DataGridCollectionView( Orders, typeof( System.Data.DataRow ), false, false );
  collectionView.ItemProperties.Add( new DataGridItemProperty( "ShipCountry", typeof( string ) ) );
  collectionView.ItemProperties.Add( new DataGridItemProperty( "ShipCity", typeof( string ) ) );
  collectionView.ItemProperties.Add( new DataGridItemProperty( "ShipVia", typeof( int ) ) );
  DataGridItemProperty shipAddress = new DataGridItemProperty( "ShipAddress", typeof( string ) );
  shipAddress.SortComparer = new AddressComparer();
  collectionView.ItemProperties.Add( shipAddress );
  dataGridControl.ItemsSource = collectionView;

VB.NET

  Dim collectionView As New DataGridCollectionView( Orders, GetType( System.Data.DataRow ), False, False )
  collectionView.ItemProperties.Add( New DataGridItemProperty( "ShipCountry", GetType( String ) ) )
  collectionView.ItemProperties.Add( New DataGridItemProperty( "ShipCity", GetType( String ) ) )
  collectionView.ItemProperties.Add( New DataGridItemProperty( "ShipVia", GetType( Integer ) ) )
  Dim shipAddress As New DataGridItemProperty( "ShipAddress", GetType( String ) )
  shipAddress.SortComparer = New AddressComparer()
  collectionView.ItemProperties.Add( shipAddress )
  dataGridControl.ItemsSource = collectionView

The following code provides the implementation of the AddressComparer class.

C#

  using System;
  using System.Collections;
  using System.Data;
  namespace Xceed.Wpf.Documentation
  {
  public class AddressComparer: IComparer
  {
    public AddressComparer()
    {
    }
    int IComparer.Compare( object x, object y )
    {
      string stringX = ( string )x;
      string stringY = ( string )y;
      const string digits = "0123456789";
      if( ( digits.IndexOf( stringX[ 0 ] ) >= 0 ) && ( digits.IndexOf( stringY[ 0 ] ) >= 0 ) )
      {
        int index = 0;
        System.Text.StringBuilder xNumber = new System.Text.StringBuilder();
        while( ( index < stringX.Length ) && ( digits.IndexOf( stringX[ index ] ) >= 0 ) )
        {
          xNumber.Append( stringX[ index ] );
          index++;
        }
        index = 0;
        System.Text.StringBuilder yNumber = new System.Text.StringBuilder();
        while( ( index < stringY.Length ) && ( digits.IndexOf( stringY[ index ] ) >= 0 ) )
        {
          yNumber.Append( stringY[ index ] );
          index++;
        }
        long xValue = long.Parse( xNumber.ToString() );
        long yValue = long.Parse( yNumber.ToString() );
        if( xValue > yValue )
          return 1;
        if( xValue < yValue )
          return -1;
        return stringX.CompareTo( stringY );
      }
      else
      {
        return stringX.CompareTo( stringY );
      }
    }
  }
  }

VB.NET

  Imports System
  Imports System.Collections
  Imports System.Data
  Namespace Xceed.Wpf.Documentation
    Public Class AddressComparer
                Implements IComparer
      Public Sub New()
      End Sub
      Public Function Compare( x As Object, y As Object ) As Integer Implements IComparer.Compare
        Dim stringX As String = CType( x, String )
        Dim stringY As String = Ctyle( y, String )
        Const digits As String = "0123456789"
        If( ( digits.IndexOf( stringX( 0 ) ) >= 0 ) And ( digits.IndexOf( stringY( 0 ) ) >= 0 ) ) Then
          Dim index As Integer = 0
          Dim xNumber As System.Text.StringBuilder = New System.Text.StringBuilder()
          While( ( index < stringX.Length ) And ( digits.IndexOf( stringX( index ) ) >= 0 ) )
            xNumber.Append( stringX( index ) )
            index++
          End While
          index = 0
          Dim yNumber As System.Text.StringBuilder = New System.Text.StringBuilder()
          While( ( index < stringY.Length ) And ( digits.IndexOf( stringY( index ) ) >= 0 ) )
            yNumber.Append( stringY( index ) )
            index++
          End While
          Dim xValue = Long.Parse( xNumber.ToString() )
          Dim yValue As Long = Long.Parse( yNumber.ToString() )
          If( xValue > yValue ) Then
            Return 1
          End If
          If( xValue < yValue ) Then
            Return -1
          End If
          Return stringX.CompareTo( stringY )
        Else
          Return stringX.CompareTo( stringY )
        End If
      End Function
    End Class
  End Namespace