From 7858206e1bc6d27e86abb070d8836b4460dc1185 Mon Sep 17 00:00:00 2001
From: CuiLiang <cuiliang.bj@gmail.com>
Date: Thu, 24 Jun 2021 13:28:17 +0800
Subject: [PATCH] always visible scrollbar different opacity for mousehover

---
 .../Styles/Base/ScrollViewerBaseStyle.xaml    | 32 +++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/Shared/HandyControl_Shared/Themes/Styles/Base/ScrollViewerBaseStyle.xaml b/src/Shared/HandyControl_Shared/Themes/Styles/Base/ScrollViewerBaseStyle.xaml
index 3d818006..89fc7924 100644
--- a/src/Shared/HandyControl_Shared/Themes/Styles/Base/ScrollViewerBaseStyle.xaml
+++ b/src/Shared/HandyControl_Shared/Themes/Styles/Base/ScrollViewerBaseStyle.xaml
@@ -205,6 +205,24 @@
     </Style>
 
     <ControlTemplate x:Key="ScrollViewerNativeBaseControlTemplate" TargetType="ScrollViewer">
+        <ControlTemplate.Resources>
+            <Storyboard x:Key="Storyboard1">
+                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_VerticalScrollBar">
+                    <EasingDoubleKeyFrame KeyTime="0:0:.1" Value=".8"/>
+                </DoubleAnimationUsingKeyFrames>
+                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_HorizontalScrollBar">
+                    <EasingDoubleKeyFrame KeyTime="0:0:.1" Value=".8"/>
+                </DoubleAnimationUsingKeyFrames>
+            </Storyboard>
+            <Storyboard x:Key="Storyboard2">
+                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_VerticalScrollBar">
+                    <EasingDoubleKeyFrame KeyTime="0:0:.2" Value=".3"/>
+                </DoubleAnimationUsingKeyFrames>
+                <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PART_HorizontalScrollBar">
+                    <EasingDoubleKeyFrame KeyTime="0:0:.2" Value=".3"/>
+                </DoubleAnimationUsingKeyFrames>
+            </Storyboard>
+        </ControlTemplate.Resources>
         <Grid x:Name="Grid" Background="{TemplateBinding Background}">
             <Grid.ColumnDefinitions>
                 <ColumnDefinition Width="*"/>
@@ -215,9 +233,19 @@
                 <RowDefinition Height="Auto"/>
             </Grid.RowDefinitions>
             <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" Grid.RowSpan="2" Grid.ColumnSpan="2" CanContentScroll="{TemplateBinding CanContentScroll}" CanHorizontallyScroll="False" CanVerticallyScroll="False" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="0" Margin="{TemplateBinding Padding}" Grid.Row="0"/>
-            <ScrollBar x:Name="PART_VerticalScrollBar" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="VerticalScrollBar" Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}" Minimum="0" Grid.Row="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}"/>
-            <ScrollBar x:Name="PART_HorizontalScrollBar" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="HorizontalScrollBar" Cursor="Arrow" Grid.Column="0" Maximum="{TemplateBinding ScrollableWidth}" Minimum="0" Orientation="Horizontal" Grid.Row="1" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}"/>
+            <ScrollBar x:Name="PART_VerticalScrollBar" Opacity=".3" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="VerticalScrollBar" Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}" Minimum="0" Grid.Row="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}"/>
+            <ScrollBar x:Name="PART_HorizontalScrollBar"  Opacity=".3" Style="{StaticResource ScrollBarBaseStyle}" AutomationProperties.AutomationId="HorizontalScrollBar" Cursor="Arrow" Grid.Column="0" Maximum="{TemplateBinding ScrollableWidth}" Minimum="0" Orientation="Horizontal" Grid.Row="1" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}"/>
         </Grid>
+        <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+                <Trigger.EnterActions>
+                    <BeginStoryboard Storyboard="{StaticResource Storyboard1}"/>
+                </Trigger.EnterActions>
+                <Trigger.ExitActions>
+                    <BeginStoryboard Storyboard="{StaticResource Storyboard2}"/>
+                </Trigger.ExitActions>
+            </Trigger>
+        </ControlTemplate.Triggers>
     </ControlTemplate>