先看一下效果：
先分析一下滚动条有哪儿几部分组成：
滚动条总共有五部分组成：
两端的箭头按钮，实际类型为RepeatButton
Thumb 两端的空白，实际也是RepeatButton
最后就是Thumb(滑块)
所以如果要修改滚动条的样式，就要修改这五部分的样式。具体代码如下：
<!--自定义滚动条样式-->
<SolidColorBrush x:Key="StandardBorderBrush"
Color="#888" />
<SolidColorBrush x:Key="StandardBackgroundBrush"
Color="#FFF" />
<SolidColorBrush x:Key="HoverBorderBrush"
Color="#DDD" />
<SolidColorBrush x:Key="SelectedBackgroundBrush"
Color="Gray" />
<SolidColorBrush x:Key="SelectedForegroundBrush"
Color="White" />
<SolidColorBrush x:Key="DisabledForegroundBrush"
Color="#888" />
<SolidColorBrush x:Key="NormalBrush"
Color="#888" />
<SolidColorBrush x:Key="NormalBorderBrush"
Color="#888" />
<SolidColorBrush x:Key="HorizontalNormalBrush"
Color="#888" />
<SolidColorBrush x:Key="HorizontalNormalBorderBrush"
Color="#888" />
<SolidColorBrush x:Key="GlyphBrush"
Color="#444" />
<LinearGradientBrush x:Key="ListBoxBackgroundBrush"
StartPoint="0,0"
EndPoint="1,0.001">
<GradientBrush.GradientStops>
<GradientStopCollection>
<GradientStop Color="White"
Offset="0.0" />
<GradientStop Color="White"
Offset="0.6" />
<GradientStop Color="#DDDDDD"
Offset="1.2" />
</GradientStopCollection>
</GradientBrush.GradientStops>
</LinearGradientBrush>
<LinearGradientBrush x:Key="StandardBrush"
StartPoint="0,0"
EndPoint="0,1">
<GradientBrush.GradientStops>
<GradientStopCollection>
<GradientStop Color="#FFF"
Offset="0.0" />
<GradientStop Color="#CCC"
Offset="1.0" />
</GradientStopCollection>
</GradientBrush.GradientStops>
</LinearGradientBrush>
<LinearGradientBrush x:Key="PressedBrush"
StartPoint="0,0"
EndPoint="0,1">
<GradientBrush.GradientStops>
<GradientStopCollection>
<GradientStop Color="#BBB"
Offset="0.0" />
<GradientStop Color="#EEE"
Offset="0.1" />
<GradientStop Color="#EEE"
Offset="0.9" />
<GradientStop Color="#FFF"
Offset="1.0" />
</GradientStopCollection>
</GradientBrush.GradientStops>
</LinearGradientBrush>
<Style x:Key="ScrollBarLineButton"
TargetType="{x:Type RepeatButton}">
<Setter Property="SnapsToDevicePixels"
Value="True" />
<Setter Property="OverridesDefaultStyle"
Value="true" />
<Setter Property="Focusable"
Value="false" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Border Name="Border"
Margin="1"
CornerRadius="2"
Background="{StaticResource NormalBrush}"
BorderBrush="{StaticResource NormalBorderBrush}"
BorderThickness="1">
<Path HorizontalAlignment="Center"
VerticalAlignment="Center"
Fill="{StaticResource GlyphBrush}"
Data="{Binding Path=Content,
RelativeSource={RelativeSource TemplatedParent}}" />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsPressed"
Value="true">
<Setter TargetName="Border"
Property="Background"
Value="{StaticResource PressedBrush}" />
</Trigger>
<Trigger Property="IsEnabled"
Value="false">
<Setter Property="Foreground"
Value="{StaticResource DisabledForegroundBrush}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ScrollBarPageButton"
TargetType="{x:Type RepeatButton}">
<Setter Property="SnapsToDevicePixels"
Value="True" />
<Setter Property="OverridesDefaultStyle"
Value="true" />
<Setter Property="IsTabStop"
Value="false" />
<Setter Property="Focusable"
Value="false" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type RepeatButton}">
<Border Background="Transparent" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ScrollBarThumb"
TargetType="{x:Type Thumb}">
<Setter Property="SnapsToDevicePixels"
Value="True" />
<Setter Property="OverridesDefaultStyle"
Value="true" />
<Setter Property="IsTabStop"
Value="false" />
<Setter Property="Focusable"
Value="false" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Thumb}">
<Border CornerRadius="2"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="1" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<ControlTemplate x:Key="VerticalScrollBar"
TargetType="{x:Type ScrollBar}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition MaxHeight="18" />
<RowDefinition Height="0.00001*" />
<RowDefinition MaxHeight="18" />
</Grid.RowDefinitions>
<Border Grid.RowSpan="3"
CornerRadius="2"
Background="#F0F0F0" />
<RepeatButton Grid.Row="0"
Style="{StaticResource ScrollBarLineButton}"
Height="18"
Command="ScrollBar.LineUpCommand"
Content="M 0 4 L 8 4 L 4 0 Z" />
<Track Name="PART_Track"
Grid.Row="1"
IsDirectionReversed="true">
<Track.DecreaseRepeatButton>
<RepeatButton Style="{StaticResource ScrollBarPageButton}"
Command="ScrollBar.PageUpCommand" />
</Track.DecreaseRepeatButton>
<Track.Thumb>
<Thumb Style="{StaticResource ScrollBarThumb}"
Margin="1,0,1,0"
Background="{StaticResource HorizontalNormalBrush}"
BorderBrush="{StaticResource HorizontalNormalBorderBrush}" />
</Track.Thumb>
<Track.IncreaseRepeatButton>
<RepeatButton Style="{StaticResource ScrollBarPageButton}"
Command="ScrollBar.PageDownCommand" />
</Track.IncreaseRepeatButton>
</Track>
<RepeatButton Grid.Row="3"
Style="{StaticResource ScrollBarLineButton}"
Height="18"
Command="ScrollBar.LineDownCommand"
Content="M 0 0 L 4 4 L 8 0 Z" />
</Grid>
</ControlTemplate>
<ControlTemplate x:Key="HorizontalScrollBar"
TargetType="{x:Type ScrollBar}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition MaxWidth="30" />
<ColumnDefinition Width="0.00001*" />
<ColumnDefinition MaxWidth="30" />
</Grid.ColumnDefinitions>
<Border Grid.ColumnSpan="3"
CornerRadius="5"
Background="#CCCCCC" />
<RepeatButton Grid.Column="0"
Style="{StaticResource ScrollBarLineButton}"
Width="18"
Command="ScrollBar.LineLeftCommand"
Content="M 4 0 L 4 8 L 0 4 Z" Margin="10,0,2,0"/>
<Track Name="PART_Track"
Grid.Column="1"
IsDirectionReversed="False">
<Track.DecreaseRepeatButton>
<RepeatButton Style="{StaticResource ScrollBarPageButton}"
Command="ScrollBar.PageLeftCommand" />
</Track.DecreaseRepeatButton>
<Track.Thumb>
<Thumb Style="{StaticResource ScrollBarThumb}"
Margin="0,1,0,1"
Background="{StaticResource NormalBrush}"
BorderBrush="{StaticResource NormalBorderBrush}" />
</Track.Thumb>
<Track.IncreaseRepeatButton>
<RepeatButton Style="{StaticResource ScrollBarPageButton}"
Command="ScrollBar.PageRightCommand" />
</Track.IncreaseRepeatButton>
</Track>
<RepeatButton Grid.Column="3"
Style="{StaticResource ScrollBarLineButton}"
Width="18"
Margin="2,0,10,0"
Command="ScrollBar.LineRightCommand"
Content="M 0 0 L 4 4 L 0 8 Z" />
</Grid>
</ControlTemplate>
<Style x:Key="{x:Type ScrollBar}"
TargetType="{x:Type ScrollBar}">
<Setter Property="SnapsToDevicePixels"
Value="True" />
<Setter Property="OverridesDefaultStyle"
Value="true" />
<Style.Triggers>
<Trigger Property="Orientation"
Value="Horizontal">
<Setter Property="Width"
Value="Auto" />
<Setter Property="Height"
Value="18" />
<Setter Property="Template"
Value="{StaticResource HorizontalScrollBar}" />
</Trigger>
<Trigger Property="Orientation"
Value="Vertical">
<Setter Property="Width"
Value="18" />
<Setter Property="Height"
Value="Auto" />
<Setter Property="Template"
Value="{StaticResource VerticalScrollBar}" />
</Trigger>
</Style.Triggers>
</Style>
<Style x:Key="FavsScrollViewer"
TargetType="{x:Type ScrollViewer}">
<Setter Property="OverridesDefaultStyle"
Value="True" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ScrollViewer}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto" />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ScrollContentPresenter Grid.Column="1" />
<ScrollBar Name="PART_VerticalScrollBar"
Value="{TemplateBinding VerticalOffset}"
Maximum="{TemplateBinding ScrollableHeight}"
ViewportSize="{TemplateBinding ViewportHeight}"
Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" />
<ScrollBar Name="PART_HorizontalScrollBar"
Orientation="Horizontal"
Grid.Row="1"
Grid.Column="1"
Value="{TemplateBinding HorizontalOffset}"
Maximum="{TemplateBinding ScrollableWidth}"
ViewportSize="{TemplateBinding ViewportWidth}"
Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
XAML中代码为：
<ScrollViewer Grid.Row="1"
RenderTransformOrigin="0.5,0.5"
HorizontalAlignment="Stretch"
Margin="0"
Width="Auto"
HorizontalScrollBarVisibility="Visible"
Style="{StaticResource FavsScrollViewer}"
Focusable="True"
VerticalScrollBarVisibility="Disabled"
>
<WrapPanel x:Name="contentPanel"
Orientation="Vertical"
></WrapPanel>
</ScrollViewer>
因样式代码较多，建议先复制到项目中看一下效果，在根据滚动条的五部分内容分别研究相应的样式，本人也是知道一点总结一点，如果您有不同的简介，很高兴能和你讨论，能和大家共同进步。