Silverlight 3：事件觸發器認爲屬性超出範圍

我想在鼠標進入時使網格不透明。所以，我試圖抓住MouseEnter事件和動畫Opactity財產Silverlight 3：事件觸發器認爲屬性超出範圍

<Grid Opacity="0.1" Name="myGrid" > 
      <Grid.Triggers> 
       <EventTrigger RoutedEvent="Grid.MouseEnter" > 
        <BeginStoryboard> 
         <Storyboard> 
          <DoubleAnimation From="0.1" To="1" Duration="00:00:01" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="myGrid"/> 
         </Storyboard> 
        </BeginStoryboard> 
       </EventTrigger> 
      </Grid.Triggers> 
    </Grid>

但在InitializeComponent認爲Grid.MouseEnter屬性超出範圍。我做錯了什麼？

來源

2011-03-17 Andrew Florko