or
Telerik.Windows.Controls.GridViewColumn timeColumn = this.RadGridView1.Columns["subject_timestamp"];Telerik.Windows.Controls.GridView.IColumnFilterDescriptor timeFilter = timeColumn.ColumnFilterDescriptor;timeFilter.SuspendNotifications();timeFilter.FieldFilter.Filter1.Operator = Telerik.Windows.Data.FilterOperator.IsGreaterThan;timeFilter.FieldFilter.Filter1.Value = DateTime.Now.AddYears(-1).ToShortDateString();timeFilter.ResumeNotifications();public IQueryable<MyModel> Data{ get { return this.dataService.GetData(); }}<telerik:RadGridView Name="RadGridView1" GroupRenderMode="Flat" ShowInsertRow="True" CanUserInsertRows="True" CanUserFreezeColumns="False" ItemsSource="{Binding Data}" AutoGenerateColumns="False" SelectedItem="SelectedItem" ActionOnLostFocus="CommitEdit" RowIndicatorVisibility="Collapsed" ShowGroupPanel="False"><local:MyGridRowStyleSelector x:Key="RowStyleSelector"> <local:MyGridRowStyleSelector.MoreResultsRowStyle> <Style TargetType="telerik:TreeListViewRow" x:Name="MoreResults"> <Setter Property="telerik:TreeListViewRow.Template" Value="{StaticResource MoreDataCustomRowTemplate}" /> </Style> </local:MyGridRowStyleSelector.MoreResultsRowStyle> <local:MyGridRowStyleSelector.NormalRowStyle> <Style TargetType="telerik:TreeListViewRow" x:Name="NormalResults"> </Style> </local:MyGridRowStyleSelector.NormalRowStyle></local:MyGridRowStyleSelector><ItemsControl x:Name="PART_DataCellsPresenter" Grid.ColumnSpan="2" Grid.Column="1" ItemsSource="{Binding Path=Functions}"> <ItemsControl.ItemTemplate> <DataTemplate> <Grid> <Button Content="{Binding}" /> </Grid> </DataTemplate> </ItemsControl.ItemTemplate></ItemsControl><telerik:GridViewDataColumn ColumnGroupName="ColumnsTrans" DataMemberBinding="{Binding Value1}" DataFormatString="{}{0:f2}" IsFilterable="False" IsReadOnly="True" Width="70" FooterTextAlignment="Right" > <telerik:GridViewDataColumn.Header> <TextBlock TextWrapping="Wrap" TextAlignment="Center"> <TextBlock.Text> <Binding RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type Window}}" Path="DataContext.Label1" /> </TextBlock.Text> </TextBlock> </telerik:GridViewDataColumn.Header> <telerik:GridViewDataColumn.AggregateFunctions> <telerik:SumFunction Caption="" ResultFormatString="{}{0:N2}" ></telerik:SumFunction> </telerik:GridViewDataColumn.AggregateFunctions> </telerik:GridViewDataColumn>((IObjectContextAdapter) GearboxEntities).ObjectContext;