WPF多个DataTriggers绑定到同一个源

Question

我终于找到了故事板数据触发器问题。问题似乎发生，因为我有2个DataTriggers绑定到相同的viewmodel属性：

    <Grid Panel.ZIndex="95" Height="234" HorizontalAlignment="Left" Margin="0,85,0,0" Name="grid1" VerticalAlignment="Top" Width="64" Background="#FF454540" Opacity="1">
        <Grid.Style>
            <Style TargetType="{x:Type Grid}">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding SearchMenuState}" Value="{x:Static local:SideMenuState.Shown}">
                        <DataTrigger.EnterActions>
                            <BeginStoryboard>
                                <Storyboard>
                                    <ThicknessAnimation Duration="0:0:.1" Storyboard.TargetProperty="Margin" To="69,85,0,0" />
                                </Storyboard>
                            </BeginStoryboard>
                        </DataTrigger.EnterActions>
                    </DataTrigger>

                    <DataTrigger Binding="{Binding SearchMenuState}" Value="{x:Static local:SideMenuState.Hidden}">
                        <DataTrigger.EnterActions>
                            <BeginStoryboard>
                                <Storyboard>
                                    <ThicknessAnimation Duration="0:0:.1" Storyboard.TargetProperty="Margin" To="0,85,0,0" />
                                </Storyboard>
                            </BeginStoryboard>
                        </DataTrigger.EnterActions>
                    </DataTrigger>

                </Style.Triggers>
            </Style>

当我注释掉第二个DataTrigger时，第一个可以工作。为什么会这样，我怎样才能纠正它以便两者都有效？