wpf - EventToCommand が起動しない

Question

eventToCommand を使用して、ユーザーがいつスライダー コントロールにマウスを置いたかを判断しようとしています。ただし、解雇されることはありません。これはデータ テンプレートに含まれています

<DataTemplate x:Key="RunEventsTemplate">
    <di:DIGroupBox Grid.Row="2" Header="Real-Time Modifications" DataContext="{Binding DataContext.ScenarioHelper.EventPlayingService,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Page}}}" >
        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto" />
                <RowDefinition />
                <RowDefinition />
                <RowDefinition />
            </Grid.RowDefinitions>
            <di:DIGroupBox Header="Audio" DataContext="{Binding CurrentAudioEvent}">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition />
                        <RowDefinition />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>
                    <di:DILabel Content="Filename: " />
                    <di:DIComboBox Grid.Column="1" />
                    <di:DICheckBox Grid.Row="1">Loop Audio File?</di:DICheckBox>
                    <di:DIImageToggleButton Grid.Row="1" Grid.Column="1" Height="23" Width="23" HorizontalAlignment="Left" Image="PlayIcon_White"></di:DIImageToggleButton>
                </Grid>
            </di:DIGroupBox>
            <di:DIGroupBox Grid.Row="1" Header="Odors">
                <ItemsControl ItemsSource="{Binding VehicleOdors}" ItemTemplate="{StaticResource ScentTemplate}">
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <WrapPanel></WrapPanel>
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                </ItemsControl>
            </di:DIGroupBox>
            <di:DIGroupBox Grid.Row="2" Header="Lighting" DataContext="{Binding CurrentLightingEvent}">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition />
                        <RowDefinition />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width=".3*" />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>
                    <di:DILabel Content="Color: " />
                    <di:DILabel Grid.Row="1" Content="Strobe: " />
                    <StackPanel Grid.Column="1" Orientation="Horizontal">
                        <di:DIRadioButton DIRadioButtonStyle="ToggleButton" IsChecked="{Binding CurrentDMXLightColor,Converter={StaticResource enumConverter},ConverterParameter={x:Null}}" Content="Off" Margin="0,0,5,0" Height="23" Width="50"></di:DIRadioButton>
                        <di:DIRadioButton DIRadioButtonStyle="ToggleButton" IsChecked="{Binding CurrentDMXLightColor,Converter={StaticResource enumConverter},ConverterParameter=White}" Content="White" Margin="0,0,5,0" Height="23" Width="50" />
                        <di:DIRadioButton DIRadioButtonStyle="ToggleButton" IsChecked="{Binding CurrentDMXLightColor,Converter={StaticResource enumConverter},ConverterParameter=Red}" Content="Red" Margin="0,0,5,0" Height="23" Width="50"/>
                        <di:DIRadioButton DIRadioButtonStyle="ToggleButton" IsChecked="{Binding CurrentDMXLightColor,Converter={StaticResource enumConverter},ConverterParameter=Blue}" Content="Blue"  Height="23" Width="50"/>
                    </StackPanel>
                    <StackPanel Grid.Row="1" Grid.Column="1" Orientation="Horizontal" VerticalAlignment="Center">
                        <TextBlock Text="Always On" Foreground="White" VerticalAlignment="Center" TextWrapping="Wrap" MaxWidth="50" Margin="0,0,5,0" />
                        <di:DISlider Minimum="0" Maximum="100" Value="{Binding StrobeRate}" >
                            <i:Interaction.Triggers>
                                <i:EventTrigger EventName="MouseUp">
                                      <cmd:EventToCommand Command="{Binding UserChangedSliderValueCommand}"></cmd:EventToCommand>
                                </i:EventTrigger>
                            </i:Interaction.Triggers>
                        </di:DISlider>
                        <TextBlock Text="Fast Strobe" Foreground="White" VerticalAlignment="Center" TextWrapping="Wrap" MaxWidth="50" />
                    </StackPanel>
                </Grid>
            </di:DIGroupBox>
            <di:DIGroupBox Header="Smoke" Grid.Row="3" DataContext="{Binding CurrentSmokeEvent}">
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="60" />
                        <ColumnDefinition Width="Auto" />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>
                    <di:DIToggleButton Content="Off" Width="50" Height="23">
                       </di:DIToggleButton>
                    <di:DILabel Grid.Column="1" Content="Intensity:" Margin="10,0,0,0" />
                    <di:DISlider Grid.Column="2" VerticalAlignment="Center" Value="{Binding Intensity}" Minimum="0" Maximum="100" >

                    </di:DISlider>
                </Grid>
            </di:DIGroupBox>
        </Grid>
    </di:DIGroupBox>
</DataTemplate>

コマンドは次のようになります

 private RelayCommand userChangedSliderValueCommand;
    public RelayCommand UserChangedSliderValueCommand
    {
        get 
        {
            return userChangedSliderValueCommand = (userChangedSliderValueCommand??new RelayCommand(() =>
                {
                    LightingEvent newLe = new LightingEvent();
                    newLe.DMXLightColor = CurrentDMXLightColor;
                    newLe.StrobeRate = StrobeRate;
                    UserAddNewEvent(newLe);
                }
                )); 
        }
    }

ブレークポイントを設定しましたが、ヒットすることはありません。私は.net 4.5を使用しています