3rdpartylibs/fastreports.wpf/Demos/WPF/Main/Controls/DescriptionControl.xaml

<UserControl x:Class="WpfDemo.DescriptionControl" Style="{DynamicResource Style1}"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:WpfDemo">
    <UserControl.Resources>
        <Style x:Key="Style1" TargetType="UserControl">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="local:DescriptionControl">
                        <StackPanel MaxWidth="600">
                            <ToggleButton x:Name="button" IsChecked="True" Width="90" Height="22" HorizontalAlignment="Right" Background="White" BorderBrush="LightGray">
                                <StackPanel Orientation="Horizontal">
                                    <Path Data="M0,0.5 L7,0.5 M0,2.5 L7,2.5 M0,4.5 L7,4.5" Stroke="Black" VerticalAlignment="Center"/>
                                    <TextBlock Text="{TemplateBinding Header}" Margin="6,0,0,0"/>
                                </StackPanel>
                            </ToggleButton>
                            <Grid x:Name="callout" Visibility="Collapsed" Margin="0,0,-3,0">
                                <Path Data="M0,16 L16,0 L32,16 Z" Width="32" Height="12" Fill="WhiteSmoke" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,0,20,0" Panel.ZIndex="1"/>
                                <Path Data="M0,16 L16,0 L32,16" Width="32" Height="12" Stroke="LightGray" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="0,0,20,0" Panel.ZIndex="2"/>
                                <Border Background="WhiteSmoke" BorderThickness="1" BorderBrush="LightGray" Margin="0,11,0,0">
                                    <Border.Effect>
                                        <DropShadowEffect Color="LightGray" ShadowDepth="1" Direction="270" />
                                    </Border.Effect>
                                    <StackPanel>
                                        <TextBlock Text="{TemplateBinding Description}" Padding="10" TextWrapping="Wrap"/>
                                        <TextBlock x:Name="hyperlink" Padding="10">
                                            <Hyperlink Click="Hyperlink_Click">
                                                <TextBlock Text="{TemplateBinding LinkText}"/>
                                            </Hyperlink>
                                        </TextBlock>
                                    </StackPanel>
                                </Border>
                            </Grid>
                        </StackPanel>
                        <ControlTemplate.Triggers>
                            <Trigger SourceName="button" Property="IsChecked" Value="True">
                                <Setter TargetName="callout" Property="Visibility" Value="Visible"/>
                                <Trigger.EnterActions>
                                    <BeginStoryboard>
                                        <Storyboard>
                                            <DoubleAnimation From="0" To="1" Duration="0:0:0.3" Storyboard.TargetName="callout" Storyboard.TargetProperty="Opacity"/>
                                        </Storyboard>
                                    </BeginStoryboard>
                                </Trigger.EnterActions>
                            </Trigger>
                            <Trigger Property="Description" Value="">
                                <Setter TargetName="callout" Property="Visibility" Value="Collapsed"/>
                            </Trigger>
                            <Trigger Property="Link" Value="">
                                <Setter TargetName="hyperlink" Property="Visibility" Value="Collapsed"/>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </UserControl.Resources>
</UserControl>