Я фактически решил свою проблему вчера вечером, полностью переопределив шаблон для BarDataPoint.
Стиль XAML:
<Style x:Key="NewDataPointStyle" TargetType="chartingToolkit:BarDataPoint">
<Setter Property="Background" Value="SteelBlue" />
<Setter Property="IsTabStop" Value="False" />
<Setter Property="BorderBrush" Value="#FF686868" />
<Setter Property="Width" Value="20" />
<Setter Property="Height" Value="20" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="chartingToolkit:BarDataPoint">
<Grid x:Name="Root" Opacity="1">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.1" />
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal" />
<VisualState x:Name="MouseOver">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="MouseOverHighlight" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.3" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="SelectionStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.1" />
</VisualStateGroup.Transitions>
<VisualState x:Name="Unselected" />
<VisualState x:Name="Selected">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="SelectionHighlight" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.185" />
</DoubleAnimationUsingKeyFrames>
<ColorAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="SelectionHighlight" Storyboard.TargetProperty="(Shape.Fill).(SolidColorBrush.Color)">
<SplineColorKeyFrame KeyTime="00:00:00" Value="#FF8A8A8A" />
</ColorAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="RevealStates">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.5" />
</VisualStateGroup.Transitions>
<VisualState x:Name="Shown">
<Storyboard>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:00.0010000" Storyboard.TargetName="Root" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="1" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Hidden">
<Storyboard>
<DoubleAnimation Duration="0" Storyboard.TargetName="Root" Storyboard.TargetProperty="Opacity" To="0" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ToolTipService.ToolTip>
<ContentControl Content="{Binding Path=Event_Description}" />
</ToolTipService.ToolTip>
<StackPanel Orientation="Horizontal"
Background="{TemplateBinding Background}">
</StackPanel>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
Диаграмма XAML:
<chartingToolkit:Chart x:Name="MetricChart" HorizontalAlignment="Left" Width="464" Height="352" VerticalAlignment="Top">
<chartingToolkit:Chart.Axes>
<chartingToolkit:LinearAxis Interval="10" Maximum="100" x:Name="XAxis" Orientation="X" Title="Percent Contribution (%)"/>
<chartingToolkit:CategoryAxis Title="Event Number" Orientation="Y"/>
</chartingToolkit:Chart.Axes>
<chartingToolkit:Chart.Series>
<chartingToolkit:BarSeries x:Name="MainSeries"
Title="Contribution to Risk and Errors (%)"
IndependentValueBinding="{Binding}"
DependentValueBinding="{Binding}" BorderThickness="0" BorderBrush="Black" Background="Black" OpacityMask="Black">
<chartingToolkit:BarSeries.DataPointStyle>
<Style
BasedOn="{StaticResource NewDataPointStyle}"
TargetType="{x:Type chartingToolkit:BarDataPoint}">
</Style>
</chartingToolkit:BarSeries.DataPointStyle>
</chartingToolkit:BarSeries>
</chartingToolkit:Chart.Series>
<chartingToolkit:Chart.LegendStyle>
<Style TargetType="Control">
<Setter Property="Width" Value="0"/>
<Setter Property="Height" Value="0"/>
</Style>
</chartingToolkit:Chart.LegendStyle>
</chartingToolkit:Chart>
Code-Behind:
//highestWeightedEvents is a DataTable
highestWeightedEvents = BuildHighestWeightedEventsTable();
MainSeries.DependentValueBinding = new Binding("Cutset_Frequency");
MainSeries.IndependentValueBinding = new Binding("Event_Number");
MainSeries.ItemsSource = highestWeightedEvents.DefaultView;
Так как я определяю DataSeries.ItemsSource в коде позади, привязка ToolTip знает, где искать.Я надеюсь, что кто-то еще может извлечь выгоду из этого, поскольку я потратил целый день, выясняя это: D