ShrlAlgoToolkit/WPFluent/Controls/NavigationView/NavigationLeftFluent.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:WPFluent.Controls">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="pack://application:,,,/WPFluent;component/Controls/NavigationView/NavigationViewConstants.xaml" />
    </ResourceDictionary.MergedDictionaries>

    <ControlTemplate x:Key="LeftFluentNavigationViewItemTemplate" TargetType="{x:Type controls:NavigationViewItem}">
        <Border
            x:Name="MainBorder"
            Width="{StaticResource PaneFluentButtonWidth}"
            Height="{StaticResource PaneFluentButtonHeight}"
            Padding="4"
            HorizontalAlignment="Stretch"
            Background="Transparent"
            BorderBrush="{TemplateBinding BorderBrush}"
            BorderThickness="1"
            CornerRadius="4">
            <Grid>
                <Rectangle
                    x:Name="ActiveRectangle"
                    Width="3"
                    Height="24"
                    Margin="-4,0,0,0"
                    HorizontalAlignment="Left"
                    VerticalAlignment="Center"
                    Fill="{DynamicResource NavigationViewSelectionIndicatorForeground}"
                    Opacity="0.0"
                    RadiusX="2"
                    RadiusY="2" />

                <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="*" />
                        <RowDefinition Height="Auto" />
                    </Grid.RowDefinitions>

                    <ContentPresenter
                        x:Name="IconContentPresenter"
                        Grid.Row="0"
                        Margin="0"
                        Content="{TemplateBinding Icon}"
                        TextElement.FontSize="{StaticResource NavigationViewFluentIconSize}"
                        TextElement.Foreground="{DynamicResource NavigationViewItemForegroundLeftFluent}" />

                    <Grid
                        x:Name="ContentGrid"
                        Grid.Row="1"
                        Height="{StaticResource NavigationViewFluentIconSize}"
                        Margin="0,2,0,0">
                        <ContentPresenter
                            x:Name="ElementContentPresenter"
                            HorizontalAlignment="Center"
                            Content="{TemplateBinding Content}"
                            TextElement.FontSize="{TemplateBinding FontSize}"
                            TextElement.Foreground="{DynamicResource NavigationViewItemForegroundLeftFluent}" />
                    </Grid>

                    <ContentPresenter
                        x:Name="PART_InfoBadge"
                        Grid.Row="0"
                        Margin="0"
                        HorizontalAlignment="Right"
                        VerticalAlignment="Top"
                        Content="{TemplateBinding InfoBadge}" />
                </Grid>
            </Grid>
        </Border>
        <ControlTemplate.Triggers>
            <Trigger Property="IsActive" Value="True">
                <Setter TargetName="ActiveRectangle" Property="Opacity" Value="1.0" />
                <Setter TargetName="MainBorder" Property="Background" Value="{DynamicResource NavigationViewItemBackgroundSelectedLeftFluent}" />
                <Setter TargetName="IconContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource NavigationViewSelectionIndicatorForeground}" />
                <Setter TargetName="ElementContentPresenter" Property="Margin" Value="0" />
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation
                                Storyboard.TargetName="ContentGrid"
                                Storyboard.TargetProperty="Height"
                                From="{StaticResource NavigationViewFluentIconSize}"
                                To="0"
                                Duration="0:0:.16" />
                            <DoubleAnimation
                                Storyboard.TargetName="ContentGrid"
                                Storyboard.TargetProperty="Opacity"
                                From="1"
                                To="0"
                                Duration="0:0:.16" />
                            <DoubleAnimation
                                Storyboard.TargetName="MainBorder"
                                Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Opacity)"
                                From="0"
                                To="1"
                                Duration="0:0:.16" />
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
                <Trigger.ExitActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <DoubleAnimation
                                Storyboard.TargetName="ContentGrid"
                                Storyboard.TargetProperty="Height"
                                From="0"
                                To="{StaticResource NavigationViewFluentIconSize}"
                                Duration="0:0:.16" />
                            <DoubleAnimation
                                Storyboard.TargetName="ContentGrid"
                                Storyboard.TargetProperty="Opacity"
                                From="0"
                                To="1"
                                Duration="0:0:.16" />
                            <DoubleAnimation
                                Storyboard.TargetName="MainBorder"
                                Storyboard.TargetProperty="(Border.BorderBrush).(SolidColorBrush.Opacity)"
                                From="1"
                                To="0"
                                Duration="0:0:.16" />
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.ExitActions>
            </Trigger>
            <Trigger Property="Icon" Value="{x:Null}">
                <Setter TargetName="IconContentPresenter" Property="Visibility" Value="Collapsed" />
            </Trigger>
            <Trigger Property="InfoBadge" Value="{x:Null}">
                <Setter TargetName="PART_InfoBadge" Property="Margin" Value="0" />
                <Setter TargetName="PART_InfoBadge" Property="Visibility" Value="Collapsed" />
            </Trigger>
            <Trigger Property="IsMouseOver" Value="True">
                <Setter TargetName="MainBorder" Property="Background" Value="{DynamicResource NavigationViewItemBackgroundSelectedLeftFluent}" />
            </Trigger>
            <MultiTrigger>
                <MultiTrigger.Conditions>
                    <Condition Property="IsMouseOver" Value="True" />
                    <Condition Property="IsActive" Value="False" />
                </MultiTrigger.Conditions>
                <MultiTrigger.Setters>
                    <Setter TargetName="IconContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource NavigationViewItemForegroundPointerOverLeftFluent}" />
                    <Setter TargetName="ContentGrid" Property="TextElement.Foreground" Value="{DynamicResource NavigationViewItemForegroundPointerOverLeftFluent}" />
                </MultiTrigger.Setters>
            </MultiTrigger>
            <!--
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsActive" Value="False" />
                            <Condition Property="IsMouseOver" Value="True" />
                        </MultiTrigger.Conditions>
                        <MultiTrigger.Setters>
                            <Setter TargetName="MainBorder" Property="Background" Value="{DynamicResource ControlFillColorDefault}" />
                        </MultiTrigger.Setters>
                    </MultiTrigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsActive" Value="True" />
                            <Condition Property="IsMouseOver" Value="True" />
                        </MultiTrigger.Conditions>
                        <MultiTrigger.Setters>
                            <Setter TargetName="MainBorder" Property="Background" Value="{DynamicResource ControlFillColorDefault}" />
                        </MultiTrigger.Setters>
                    </MultiTrigger>
            -->
        </ControlTemplate.Triggers>
    </ControlTemplate>

</ResourceDictionary>