Move background color change into ControlTemplate trigger collection

Moving the background changes inside of the ControlTemplate trigger collection changes the binding precedence order such that our "IsMouseOver" trigger is even closer to the DGR_Border than a local value set directly on the DataGrid (i.e. AlternatingRBackground) and thus takes precedence.

Author: nicolaihenriksen

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DataGrid.xaml

@@ -1,4 +1,4 @@
-<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
@@ -431,6 +431,14 @@
                                  Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.Row}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}, FallbackValue=Visible}" />
             </SelectiveScrollingGrid>
           </Border>
+          <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+              <Setter TargetName="DGR_Border" Property="Background" Value="{DynamicResource MaterialDesign.Brush.DataGrid.RowHoverBackground}" />
+            </Trigger>
+            <Trigger Property="IsSelected" Value="True">
+              <Setter TargetName="DGR_Border" Property="Background" Value="{DynamicResource MaterialDesign.Brush.DataGrid.Selected}" />
+            </Trigger>
+          </ControlTemplate.Triggers>
         </ControlTemplate>
       </Setter.Value>
     </Setter>
@@ -446,12 +454,6 @@
       </Setter.Value>
     </Setter>
     <Style.Triggers>
-      <Trigger Property="IsSelected" Value="True">
-        <Setter Property="Background" Value="{DynamicResource MaterialDesign.Brush.DataGrid.Selected}" />
-      </Trigger>
-      <Trigger Property="IsMouseOver" Value="True">
-        <Setter Property="Background" Value="{DynamicResource MaterialDesign.Brush.DataGrid.RowHoverBackground}" />
-      </Trigger>
       <Trigger Property="IsNewItem" Value="True">
         <Setter Property="Margin" Value="{Binding NewItemMargin, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}, FallbackValue=0}" />
       </Trigger>