SortComparer Property (DataGridItemPropertyBase)

Gets or sets the custom data comparer that will be used to sort the values of the data-grid item property's associated column.

Syntax

Visual Basic
C#

'Declaration
 
Public Property SortComparer As IComparer

'Usage
 
Dim instance As DataGridItemPropertyBase
Dim value As IComparer
 
instance.SortComparer = value
 
value = instance.SortComparer

public IComparer SortComparer {get; set;}

Property Value

The IComparer that will be used to sort the values of the DataGridItemProperty's associated column. Can be a null reference (Nothing in Visual Basic).

Remarks

If a null reference (Nothing in Visual Basic), the default comparer will be used.

Custom sort comparers are not supported by the virtualizing collection views (e.g., DataGridVirtualizingCollectionViewSource).

Example

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

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}}">          
      <xcdg:DataGridControl.View> 
         <xcdg:TableView ColumnStretchMode="StretchAll"/> 
      </xcdg:DataGridControl.View> 
   </xcdg:DataGridControl> 
</Grid>

The following code provides the implementation of the AddressComparer class.

Visual Basic

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

The following code provides the implementation of the AddressComparer class.

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 );
    }
  }
}
}

Requirements

Target Platforms: Windows 11, Windows 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

DataGridItemPropertyBase Class
DataGridItemPropertyBase Members