I want to add a button above all column in Charts in the Silverlight Toolkit.
Same with this Picture:

I add style for DataPointStyle:
<Style x:Key="ColorByGradeColumn" TargetType="toolkit:ColumnDataPoint">
<Setter Property="Background" Value="DarkGray"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="toolkit:ColumnDataPoint">
<Border
MouseEnter="Border_MouseEnter"
MouseLeave="Border_MouseLeave"
Background="{Binding Legend.Color,
Converter={StaticResource stringToSolidColorBrushConverter}}"
BorderThickness="0.5"
Tag="{Binding Legend}"
MouseLeftButtonUp="Col_MouseLeftButtonUp">
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
but i don't know where i should add button.
You can add anything you need to the
ControlTemplate.In your case this would mean you have to add a
Panel(e.g. aGrid) to arrange the button and the bar: