Add SelectedCellBorderBrush attached property (#2800)

* add SelectedCellBorderBrush attached property

* add demo datagrid

* remove Inherits

Author: ElieTaillard

MainDemo.Wpf/DataGrids.xaml

@@ -172,6 +172,17 @@
                 materialDesign:DataGridAssist.ColumnHeaderPadding="4 2 2 2" />
 
         </smtx:XamlDisplay>
+
+        <TextBlock
+            Style="{StaticResource MaterialDesignHeadline6TextBlock}"
+            Text="Custom Selected Cell Border Brush" Margin="0 24 0 0"/>
+
+        <smtx:XamlDisplay UniqueKey="grids_4">
+            <DataGrid
+                ItemsSource="{Binding Items1}"
+                CanUserAddRows="False"
+                materialDesign:DataGridAssist.SelectedCellBorderBrush="Crimson" />
+        </smtx:XamlDisplay>
     </StackPanel>
 </UserControl>
 

MaterialDesignThemes.Wpf/DataGridAssist.cs

@@ -4,6 +4,7 @@
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
 using System.Windows.Input;
+using System.Windows.Media;
 
 namespace MaterialDesignThemes.Wpf
 {
@@ -136,6 +137,17 @@ public static void SetCellPadding(DataGrid element, Thickness value)
             => element.SetValue(CellPaddingProperty, value);
         #endregion
 
+        #region AttachedProperty : SelectedCellBorderBrushProperty
+        public static readonly DependencyProperty SelectedCellBorderBrushProperty
+            = DependencyProperty.RegisterAttached("SelectedCellBorderBrush", typeof(Brush), typeof(DataGridAssist),
+                new PropertyMetadata(null));
+
+        public static Brush GetSelectedCellBorderBrush(DataGrid element)
+            => (Brush)element.GetValue(SelectedCellBorderBrushProperty);
+        public static void SetSelectedCellBorderBrush(DataGrid element, Brush value)
+            => element.SetValue(SelectedCellBorderBrushProperty, value);
+        #endregion
+
         #region AttachedProperty : ColumnHeaderPaddingProperty
         public static readonly DependencyProperty ColumnHeaderPaddingProperty
             = DependencyProperty.RegisterAttached("ColumnHeaderPadding", typeof(Thickness), typeof(DataGridAssist),

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DataGrid.xaml

@@ -295,7 +295,7 @@
         </Setter>
         <Style.Triggers>
             <Trigger Property="IsKeyboardFocusWithin" Value="True">
-                <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesignTextBoxBorder}" />
+                <Setter Property="BorderBrush" Value="{Binding RelativeSource={RelativeSource AncestorType=DataGrid}, Path=(wpf:DataGridAssist.SelectedCellBorderBrush)}" />
             </Trigger>
             <MultiDataTrigger>
                 <MultiDataTrigger.Conditions>
@@ -527,6 +527,7 @@
         <Setter Property="wpf:DataGridAssist.AutoGeneratedTextStyle" Value="{StaticResource MaterialDesignDataGridTextColumnStyle}" />
         <Setter Property="wpf:DataGridAssist.AutoGeneratedEditingTextStyle" Value="{StaticResource MaterialDesignDataGridTextColumnEditingStyle}" />
         <Setter Property="wpf:DataGridAssist.EnableEditBoxAssist" Value="True" />
+        <Setter Property="wpf:DataGridAssist.SelectedCellBorderBrush" Value="{DynamicResource MaterialDesignTextBoxBorder}"/>
         <Setter Property="Template">
             <Setter.Value>
                 <ControlTemplate TargetType="{x:Type DataGrid}">