斑竹看过来，关于datagrid控件有个问题

Question

http://filteringdatagrid.codeplex.com/releases/31984/download/80579

这个地方可以用个FilterDataGrid控件，我看了例子很好用，但是我在源代码中稍作修改点击排序和filter还有外面的scrollbar都不好用了，排序时间变成，scrollbar消失，很怪，我只是在上面想加个条件选择过滤的查询功能：

 

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:Labs.Filtering"
    xmlns:my="http://schemas.microsoft.com/wpf/2008/toolkit" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    x:Class="Labs.Filtering.Window1"
     Title="Window1" Height="468" Width="784"
    mc:Ignorable="d">
    <Canvas>
        <GroupBox Height="61" Header="查询条件" Width="762">
            <Canvas>
                <Button Name="btnErroOnly" Height="22" Canvas.Left="6" Canvas.Top="2" Width="68"  >仅显示错误</Button>
                <Button Canvas.Left="89" Canvas.Top="2" Height="22" Name="btnWarningOnly" Width="68"  >仅显示警告</Button>
            </Canvas>
        </GroupBox>
        <Grid></Grid>
        <local:FilteringDataGrid IsFilteringCaseSensitive="False" ItemsSource="{Binding}" IsReadOnly="True" AutoGenerateColumns="False" x:Name="dataGrid1" Height="234" Canvas.Left="0" Canvas.Top="67" Width="531">
            <my:DataGrid.Columns>
                <my:DataGridTextColumn Header="事件号" Binding="{Binding Path=Name}" />
            </my:DataGrid.Columns>
        </local:FilteringDataGrid>
    </Canvas>
</Window>

原来的代码：

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:Labs.Filtering"
     xmlns:my="http://schemas.microsoft.com/wpf/2008/toolkit" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" x:Class="Labs.Filtering.Window1"
     Title="Window1" Height="468" Width="784" mc:Ignorable="d">
 
 
    <Grid>
        <local:FilteringDataGrid IsFilteringCaseSensitive="False" ItemsSource="{Binding}" IsReadOnly="True" AutoGenerateColumns="True" x:Name="dataGrid1"/>
    </Grid>
</Window>

原来的好用，我家了点东西后发现scrollbar没有了，排序的点击花时间也长了，why？