wpf TemplatedBinding 问题求助

Question

模板 texblock属性：
HorizontalAlignment="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=HorizontalAlignment,Mode=OneWayToSource}"

模板 storeboard:

 <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)" Storyboard.TargetName="BtnBlock">       
<DiscreteObjectKeyFrame KeyTime="0" Value="{x:Static HorizontalAlignment.Left}"/>
</ObjectAnimationUsingKeyFrames> 

目标元素：

 <WrapPanel Name="WplMinPrintSet" MaxWidth="300">          
<Button Name="oooxxx" Style="{StaticResource BtnMoveSty}" Content="卧巢" />
</WrapPanel>

问题：目标元素属性值一直为Stretch,就算用目标Tag作为绑定对象，值也为Stretch。看界面操作效果是没问题的，每个Store都能正常显示texblockd的对齐方式。

Answer 1

http://book.51cto.com/art/201001/179749.htm