在自定义控件中，如何在对滑块值进行动画处理时获取它？

Question

WPF

情节提要将使滑块前进。随着情节提要板的移动，我需要获取滑块的当前数值。这似乎很困难。

这是我想要的代码，但是无法获取值。

我的问题是，如何在动画化时获得滑块的实际值？

TIA

<Button.Triggers>
     <EventTrigger RoutedEvent="Button.Click">
          <BeginStoryboard>
               <Storyboard Duration="0:0:10">
                     <DoubleAnimation Storyboard.TargetProperty="(RangeBase.Value)"                                                                    
                            Storyboard.TargetName="PART_RecordingProgressBar"
                                  From="{Binding ElementName=PART_RecordingProgressBar, Path=Value, Mode=OneWay}"
                                  To="{Binding ElementName=PART_RecordingProgressBar, Path=Maximum, Mode=OneWay}"
                                  FillBehavior="HoldEnd"
***THIS FAILS! **** Value ="{Binding Path= CurrentValue, RelativeSource={RelativeSource TemplatedParent}, Mode=OneWayToSource}"
                                     >

                    </DoubleAnimation>
             </Storyboard>
         </BeginStoryboard>
     </EventTrigger>
 </Button.Triggers>

以下是XAML（已删除的内容）：

  <Style TargetType="{x:Type local:AudioRecorder}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:AudioRecorder}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                        <Grid>
                            <StackPanel Orientation="Horizontal">

                                <Button x:Name="FastForward" Height="20">
                                    <Button.Template>
                                        <ControlTemplate TargetType="{x:Type Button}">
                                            <Border>
                                                <Viewbox Stretch="Fill">
                                                    <Path Stroke="Black" Data=" F1
                                                        M 0 0     V40  L 34.6 20  Z
                                                        M 17.3 0  V40  L 51.9 20  Z"  Fill="LightBlue" />
                                                </Viewbox>
                                            </Border>
                                        </ControlTemplate>
                                    </Button.Template>
                                    <Button.Triggers>
                                        <EventTrigger RoutedEvent="Button.Click">
                                            <BeginStoryboard>
                                                <Storyboard Duration="0:0:10">

                                                    <DoubleAnimation Storyboard.TargetProperty="(RangeBase.Value)"  
                                                                     Storyboard.TargetName="PART_RecordingProgressBar"
                                                                     From="{Binding ElementName=PART_RecordingProgressBar, Path=Value, Mode=OneWay}"
                                                                     To="{Binding ElementName=PART_RecordingProgressBar, Path=Maximum, Mode=OneWay}"
                                                                     FillBehavior="HoldEnd"
          Value ="{Binding Path= CurrentValue, RelativeSource={RelativeSource TemplatedParent}, Mode=OneWayToSource}"
                                                                     >

                                                    </DoubleAnimation>
                                                </Storyboard>
                                            </BeginStoryboard>
                                        </EventTrigger>
                                    </Button.Triggers>
                                </Button>

<Popup  Name="Popup" 
                                Placement="Bottom" PlacementTarget="{Binding ElementName=OpenRecorder}"
                                AllowsTransparency="True" Focusable="False" StaysOpen="True" IsOpen="False" PopupAnimation="None">
                            <Grid Name="DropDown" SnapsToDevicePixels="True" MinWidth="{TemplateBinding ActualWidth}">

                                            <Slider x:Name="PART_RecordingProgressBar" 
                                                        IsMoveToPointEnabled="True"
                                                        Maximum="{Binding Path=CurrentTrackLength, RelativeSource={RelativeSource TemplatedParent}, Mode=OneWay}" 
                                                        Value="{Binding Path=CurrentTrackPosition, RelativeSource={RelativeSource TemplatedParent}, Mode=TwoWay}"
                                                        HorizontalAlignment="Left" Height="22" Margin="15,423,0,0" VerticalAlignment="Top" Width="375"  />



                                        </Grid>
                                    </Border>

                                    <Button Name="closeButton" Content="Exit" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="73"/>
                                </Grid>
                            </Popup>
                        </Grid>
                    </Border>

                    <ControlTemplate.Triggers>

                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>