FilterExpression Property (DataGridControl)

Gets or sets the filter expression, which is embedded into the data query that is used to request data and filter the items that are displayed in a grid.

Syntax

Visual Basic
C#

'Declaration
 
Public Property FilterExpression As FilterExpressionBase

'Usage
 
Dim instance As DataGridControl
Dim value As FilterExpressionBase
 
instance.FilterExpression = value
 
value = instance.FilterExpression

public FilterExpressionBase FilterExpression {get; set;}

Property Value

A FilterExpressionBase representing the filter expression, which is embedded into the data query that is used to request data and filter the items that are displayed in a grid.

Example

XAML

<sldg:DataGridControl x:Name="sldgDataGridControl"
                      ItemsSource="{Binding Path=Orders}">
    <sldg:DataGridControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <sldg:SignatureThemeResourceDictionary />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </sldg:DataGridControl.Resources>
    
    <sldg:DataGridControl.FixedHeaders>
        <CheckBox Content="Display only French-Speaking Countries"
                  Checked="CheckBox_Checked"
                  Unchecked="CheckBox_Unchecked"
                  Style="{StaticResource SignatureThemeCheckBoxStyle}"/>
        <sldg:FilterRow>
            <sldg:FilterRow.FilterExpression>
                <sldg:AndFilterExpression>
                    <sldg:FilterExpression MemberName="ShipVia"
                                           Value="3"
                                           FilterOperator="Equal" />
                    <sldg:FilterExpression MemberName="OrderDate"
                                           Value="2008/01/01"
                                           FilterOperator="GreaterThanOrEqual"
                                           IsTimeSensitive="False"/>                            
                </sldg:AndFilterExpression>
            </sldg:FilterRow.FilterExpression>
        </sldg:FilterRow>
    </sldg:DataGridControl.FixedHeaders>
</sldg:DataGridControl>

VB.NET

Private m_frenchCountries As New List( Of String)( New String( 27 )
       { "Belgium", "Benin", "Burkina-Faso", "Burundi", 
         "Cameroon", "Canada", "Central African Republic", "Chad", "Comoros", 
         "Congo", "Djibouti", "France", "Gabon", "Guinea", "Haiti", "Ivory Coast", 
         "Luxembourg", "Madagascar", "Mali", "Monaco", "Niger", "Rwanda", 
         "Senegal", "Seychelles", "Switzerland", "Togo", "Vanuatu" } ) 

Private Function CreateFilterExpression() As OrFilterExpression 
   Dim childExpressions As New List( Of FilterExpressionBase )()

   Dim country As String
   For Each country In m_frenchCountries 
      Dim expression As New FilterExpression( "ShipCountry", FilterOperator.Equal, country, False )
      childExpressions.Add( expression )
   Next country 

   Return New OrFilterExpression( childExpressions )
End Function 

Private m_filterExpression As OrFilterExpression = Nothing
Private Sub CheckBox_Checked( ByVal sender As Object, ByVal e As RoutedEventArgs )
   If m_filterExpression Is Nothing Then
      m_filterExpression = Me.CreateFilterExpression()
   End If 

   Me.sldgDataGridControl.FilterExpression = m_filterExpression
End Sub 

Private Sub CheckBox_Unchecked( ByVal sender As Object, ByVal e A RoutedEventArgs )
   Me.sldgDataGridControl.FilterExpression = Nothing
End Sub

private List<string> m_frenchCountries = new List<string>( new string[ 27 ] 
       { "Belgium", "Benin", "Burkina-Faso", "Burundi", 
         "Cameroon", "Canada", "Central African Republic", "Chad", "Comoros", 
         "Congo", "Djibouti", "France", "Gabon", "Guinea", "Haiti", "Ivory Coast", 
         "Luxembourg", "Madagascar", "Mali", "Monaco", "Niger", "Rwanda", 
         "Senegal", "Seychelles", "Switzerland", "Togo", "Vanuatu" } );

private OrFilterExpression CreateFilterExpression()
{
   List<FilterExpressionBase> childExpressions = new List<FilterExpressionBase>();

   foreach( string country in m_frenchCountries )
   {
      FilterExpression expression = new FilterExpression( "ShipCountry", FilterOperator.Equal, country, false );
      childExpressions.Add( expression );
   }

   return new OrFilterExpression( childExpressions );
}

private OrFilterExpression m_filterExpression = null;
private void CheckBox_Checked( object sender, RoutedEventArgs e )
{
   if( m_filterExpression == null )
      m_filterExpression = this.CreateFilterExpression();

   this.sldgDataGridControl.FilterExpression = m_filterExpression;
}

private void CheckBox_Unchecked( object sender, RoutedEventArgs e )
{
   this.sldgDataGridControl.FilterExpression = null;
}

Requirements

Target Platforms: Windows 7, Windows Vista, Windows XP SP3, Windows Server 2008 family

Reference

DataGridControl Class
DataGridControl Members
FilterRow Class

Manipulating Data

Filtering Data