Themes/MaterialDesignTheme.Thumb.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:local="clr-namespace:MaterialDesignThemes.Wpf">
 
  <Style x:Key="MaterialDesignThumb" TargetType="{x:Type Thumb}">
    <Setter Property="Background" Value="Transparent" />
    <Setter Property="OverridesDefaultStyle" Value="True" />
    <Setter Property="Padding" Value="8" />
    <Setter Property="SnapsToDevicePixels" Value="True" />
    <Setter Property="Template">
      <Setter.Value>
        <ControlTemplate TargetType="{x:Type Thumb}">
          <Border x:Name="PART_Border"
                  Padding="{TemplateBinding Padding}"
                  Background="{TemplateBinding Background}"
                  SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
        </ControlTemplate>
      </Setter.Value>
    </Setter>
  </Style>
 
  <Style x:Key="MaterialDesignGridRowHeaderGripper"
         TargetType="{x:Type Thumb}"
         BasedOn="{StaticResource MaterialDesignThumb}">
    <Setter Property="Cursor" Value="SizeNS" />
    <Setter Property="Height" Value="8" />
    <Setter Property="Padding" Value="0" />
  </Style>
 
  <Style x:Key="MaterialDesignGridColumnHeaderGripper"
         TargetType="{x:Type Thumb}"
         BasedOn="{StaticResource MaterialDesignThumb}">
    <Setter Property="Cursor" Value="SizeWE" />
    <Setter Property="Padding" Value="0" />
    <Setter Property="Width" Value="8" />
  </Style>
 
  <Style x:Key="MaterialDesignGridViewColumnHeaderGripper"
         TargetType="{x:Type Thumb}"
         BasedOn="{StaticResource MaterialDesignThumb}">
    <Setter Property="Template">
      <Setter.Value>
        <ControlTemplate TargetType="{x:Type Thumb}">
          <Border x:Name="PART_Border"
                  Padding="{TemplateBinding Padding}"
                  Background="{TemplateBinding Background}"
                  Cursor="SizeWE"
                  SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
        </ControlTemplate>
      </Setter.Value>
    </Setter>
    <Setter Property="Width" Value="8" />
  </Style>
 
</ResourceDictionary>