silverlight DataGrid 模板列头相关问题

    <Style TargetType="dataprimitives:DataGridColumnHeader">
                                                        <Setter Property="ContentTemplate">
                                                            <Setter.Value>
                                                                <DataTemplate>
                                                                    <StackPanel Orientation="Vertical" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
                                                                        <Border BorderThickness="0,0,0,1" BorderBrush="White">
                                                                            <StackPanel Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center">
                                                                                <TextBlock Text="登录客户数" HorizontalAlignment="Center" VerticalAlignment="Center"/>
                                                                            </StackPanel>
                                                                        </Border>
                                                                        <StackPanel Orientation="Horizontal" >
                                                                            <Rectangle Fill="White" VerticalAlignment="Stretch" Width="1" />
                                                                            <TextBlock Text="" Margin="2,0,0,0" Width="98" />
                                                                            <Rectangle Fill="White" VerticalAlignment="Stretch" Width="1" />
                                                                            <TextBlock Text=" 2009 " Margin="2,0,0,0" Width="98" x:Name="txt_today"/>
                                                                            <Rectangle Fill="White" VerticalAlignment="Stretch" Width="1" />
                                                                            <TextBlock Text=" 环比 " Margin="2,0,0,0" Width="98"/>
                                                                            <Rectangle Fill="White" VerticalAlignment="Stretch" Width="1" />
                                                                            <TextBlock Text=" 同比 " Margin="2,0,0,0" Width="95"/>
                                                                            <Rectangle Fill="White" VerticalAlignment="Stretch" Width="1" />
                                                                        </StackPanel>
                                                                    </StackPanel>
                                                                </DataTemplate>
                                                            </Setter.Value>
                                                        </Setter>
                                                    </Style>

以上为xaml代码，如何在后台给 x:Name="txt_lastYear"的控件设置当前年份值，当然前台绑定的话也可以，求达人解答

1.给你绑定的实体添加一个LastYear的属性

2.若数据库表里无LastYear的值（意味着你要自动生成），绑定的时候用Converter转换，然后写一个Converter条件判断并返回当年的年份值。