编辑模板后WPF滑块处于禁用状态

我使用最新的Blend预览来创建滑块的样式。当我运行应用程序时，滑块总是被禁用的。只要移除自定义样式，它就会再次启用。我不明白为什么会发生这种事。

Blend生成的模板代码如下:

        <Style x:Key="SliderStyle1" TargetType="Slider">
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Maximum" Value="10"/>
        <Setter Property="Minimum" Value="0"/>
        <Setter Property="Value" Value="0"/>
        <Setter Property="BorderBrush">
            <Setter.Value>
                <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                    <GradientStop Color="#FFA3AEB9" Offset="0"/>
                    <GradientStop Color="#FF8399A9" Offset="0.375"/>
                    <GradientStop Color="#FF718597" Offset="0.375"/>
                    <GradientStop Color="#FF617584" Offset="1"/>
                </LinearGradientBrush>
            </Setter.Value>
        </Setter>
        <Setter Property="IsTabStop" Value="False"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Slider">
                    <Grid x:Name="Root">
                        <Grid.Resources>
                            <ControlTemplate x:Key="RepeatButtonTemplate">
                                <Grid x:Name="Root" Background="Transparent" Opacity="0"/>
                            </ControlTemplate>
                        </Grid.Resources>
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="MouseOver"/>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="HorizontalTrackRectangleDisabledOverlay">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ThumbDisabledOverlay">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Duration="0" Storyboard.TargetProperty="Visibility" Storyboard.TargetName="VerticalTrackRectangleDisabledOverlay">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Grid x:Name="HorizontalTemplate" Background="{TemplateBinding Background}">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto"/>
                                <ColumnDefinition Width="Auto"/>
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <Rectangle x:Name="TrackRectangle" Grid.ColumnSpan="3" Grid.Column="0" Fill="#FFE6EFF7" Height="3" Margin="5,0,5,0" RadiusY="1" RadiusX="1" Stroke="#FFA3AEB9" StrokeThickness="{TemplateBinding BorderThickness}"/>
                            <Rectangle x:Name="HorizontalTrackRectangleDisabledOverlay" Grid.ColumnSpan="3" Grid.Column="0" Fill="White" Height="3" Margin="5,0,5,0" Opacity=".55" RadiusY="1" RadiusX="1" Visibility="Collapsed"/>
                            <RepeatButton x:Name="HorizontalTrackLargeChangeDecreaseRepeatButton" Grid.Column="0" Height="18" IsTabStop="False" Template="{StaticResource RepeatButtonTemplate}"/>
                            <Thumb x:Name="HorizontalThumb" Grid.Column="1" Height="18" IsTabStop="True" Width="11"/>
                            <Rectangle x:Name="ThumbDisabledOverlay" Grid.Column="1" Fill="White" Opacity=".55" RadiusY="2" RadiusX="2" Visibility="Collapsed" Width="11"/>
                            <RepeatButton x:Name="HorizontalTrackLargeChangeIncreaseRepeatButton" Grid.Column="2" Height="18" IsTabStop="False" Template="{StaticResource RepeatButtonTemplate}"/>
                        </Grid>
                        <Grid x:Name="VerticalTemplate" Background="{TemplateBinding Background}" Visibility="Collapsed">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="*"/>
                                <RowDefinition Height="Auto"/>
                                <RowDefinition Height="Auto"/>
                            </Grid.RowDefinitions>
                            <Rectangle Fill="#FFE6EFF7" Margin="0,5,0,5" RadiusY="1" Grid.Row="0" RadiusX="1" Grid.RowSpan="3" Stroke="#FFA3AEB9" StrokeThickness="{TemplateBinding BorderThickness}" Width="3"/>
                            <Rectangle x:Name="VerticalTrackRectangleDisabledOverlay" Fill="White" Margin="0,5,0,5" Opacity=".55" RadiusY="1" Grid.Row="0" RadiusX="1" Grid.RowSpan="3" Visibility="Collapsed" Width="3"/>
                            <RepeatButton x:Name="VerticalTrackLargeChangeDecreaseRepeatButton" IsTabStop="False" Grid.Row="2" Template="{StaticResource RepeatButtonTemplate}" Width="18"/>
                            <Thumb x:Name="VerticalThumb" Height="11" IsTabStop="True" Grid.Row="1" Width="18"/>
                            <RepeatButton x:Name="VerticalTrackLargeChangeIncreaseRepeatButton" IsTabStop="False" Grid.Row="0" Template="{StaticResource RepeatButtonTemplate}" Width="18"/>
                        </Grid>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>