Xceed Logo
Shop
Xceed Toolkit Plus for WPF v5.1 Documentation
Xceed.Wpf.DataGrid.Toolkit Assembly / Xceed.Wpf.DataGrid Namespace / DataGridItemPropertyBase Class / QueryDistinctValue Event
Example


In This Topic
    QueryDistinctValue Event
    In This Topic
    Raised to allow custom distinct values to be provided.
    Syntax
    'Declaration
 

    Public Event QueryDistinctValue As EventHandler(Of QueryDistinctValueEventArgs)
    'Usage
 

    Dim instance As DataGridItemPropertyBase
Dim handler As EventHandler(Of QueryDistinctValueEventArgs)
 
AddHandler instance.QueryDistinctValue, handler
    public event EventHandler<QueryDistinctValueEventArgs> QueryDistinctValue
    Event Data

    The event handler receives an argument of type QueryDistinctValueEventArgs containing data related to this event. The following QueryDistinctValueEventArgs properties provide information specific to this event.

    PropertyDescription
    DataSourceValueGets the original distinct value extracted from the underlying data source.  
    DistinctValueGets or sets the custom distinct value that replaces the one originally extracted from the underlying data source.  
    Remarks
    By default, the values that are displayed in the auto-filter drop down represent the distinct values as they are extracted from the underlying data source; however, custom distinct values can be provided for one or more item properties rather than the originally-extracted distinct values by handling their QueryDistinctValue event and returning the custom value.
    Example
    The following example demonstrates how to provide custom distinct values that will display the only the month in columns that display DateTime values and that will filter according to a value range for a decimal column.
    <Grid 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}"
                                        AutoFilterMode="And"
                                        DefaultCalculateDistinctValues="False">
        <xcdg:DataGridCollectionViewSource.ItemProperties>

          <xcdg:DataGridItemProperty Name="OrderDate"
                                     QueryDistinctValue="DataGridItemProperty_QueryDistinctValue_Date"
                                     CalculateDistinctValues="True"/>
          <xcdg:DataGridItemProperty Name="RequiredDate"
                                     QueryDistinctValue="DataGridItemProperty_QueryDistinctValue_Date"
                                     CalculateDistinctValues="True" />
          <xcdg:DataGridItemProperty Name="ShippedDate"
                                     QueryDistinctValue="DataGridItemProperty_QueryDistinctValue_Date"
                                     CalculateDistinctValues="True" />
          <xcdg:DataGridItemProperty Name="Freight"
                                     QueryDistinctValue="DataGridItemProperty_QueryDistinctValue_Range"
                                     CalculateDistinctValues="True" />
        </xcdg:DataGridCollectionViewSource.ItemProperties>
     </xcdg:DataGridCollectionViewSource>
   
  </Grid.Resources>
  <xcdg:DataGridControl x:Name="OrdersGrid"
                        ItemsSource="{Binding Source={StaticResource cvs_orders}}"/>
</Grid>
    Private Sub DataGridItemProperty_QueryDistinctValue_Date( ByVal sender As Object, ByVal e As QueryDistinctValueEventArgs )
  If Typeof e.DataSourceValue Is DateTime Then
    e.DistinctValue = CDate( e.DataSourceValue ).ToString( "MMMM" )
  End If
End Sub

Private Sub DataGridItemProperty_QueryDistinctValue_Range( ByVal sender As Object, ByVal e As QueryDistinctValueEventArgs )
  If Typeof e.DataSourceValue Is Decimal Then
    Dim value As Decimal = CDec( e.DataSourceValue )
    If value <= 100 Then
      e.DistinctValue = "0 - 100"
    ElseIf( value > 100 And value <= 500 ) Then
      e.DistinctValue = "101 - 500"
    Else
      e.DistinctValue = "500+"
    End If
  End If
End Sub
    private void DataGridItemProperty_QueryDistinctValue_Date( object sender, QueryDistinctValueEventArgs e )
{
 if( e.DataSourceValue is DateTime )
 {
   e.DistinctValue = ( ( DateTime )e.DataSourceValue ).ToString( "MMMM" );
 }
}

private void DataGridItemProperty_QueryDistinctValue_Range( object sender, QueryDistinctValueEventArgs e )
{
 if( e.DataSourceValue is decimal )
 {
   decimal value = ( decimal )e.DataSourceValue;
   if( value <= 100 )
   {
     e.DistinctValue = "0 - 100";
   }
   else if( value > 100 && value <= 500 )
   {
     e.DistinctValue = "101 - 500";
   }
   else
   {
     e.DistinctValue = "500+";
   }
 }
}
    Supported Frameworks

    .NET: net5.0, net5.0-windows, net6.0, net6.0-macos, net6.0-windows, net7.0, net7.0-macos, net7.0-windows, net8.0, net8.0-browser, net8.0-macos, net8.0-windows, net9.0, net9.0-browser, net9.0-macos, net9.0-windows, net10.0, net10.0-browser, net10.0-macos, net10.0-windows.

    .NET Framework: net40, net403, net45, net451, net452, net46, net461, net462, net463, net47, net471, net472, net48, net481.

    See Also

    Reference

    DataGridItemPropertyBase Class
    DataGridItemPropertyBase Members

    Send Feedback