using relative source binding instead

Author: xaviergonz

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.CheckBox.xaml

@@ -86,7 +86,7 @@
                             <Canvas Width="24" Height="24">
                                 <Path x:Name="Graphic"
                                       Data="M19,3H5C3.89,3 3,3.89 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5C21,3.89 20.1,3 19,3M19,5V19H5V5H19Z" 
-                                      Fill="{TemplateBinding Background}" />
+                                      Fill="{DynamicResource MaterialDesignCheckBoxOff}" />
                                 <Ellipse x:Name="InteractionEllipse" Fill="{TemplateBinding Foreground}" Width="0" Height="0" Canvas.Top="12" Canvas.Left="12" Opacity="0" RenderTransformOrigin="0.5,0.5"
                                          IsHitTestVisible="False">
                                     <Ellipse.RenderTransform>
@@ -116,14 +116,11 @@
                         <Trigger Property="IsPressed" Value="true"/>
                         <Trigger Property="IsChecked" Value="true">
                             <Setter Property="Data" TargetName="Graphic" Value="M10,17L5,12L6.41,10.58L10,14.17L17.59,6.58L19,8M19,3H5C3.89,3 3,3.89 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5C21,3.89 20.1,3 19,3Z" />
-                        </Trigger>
-                        <Trigger Property="IsChecked" Value="False">
-                          <Setter Property="Fill" TargetName="Graphic" Value="{DynamicResource MaterialDesignCheckBoxOff}" />
+                            <Setter Property="Fill" TargetName="Graphic" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Background}" />
                         </Trigger>
                         <Trigger Property="IsChecked" Value="{x:Null}">
                             <Setter Property="Data" TargetName="Graphic" Value="M10,17L5,12L6.41,10.58L10,14.17L17.59,6.58L19,8M19,3H5C3.89,3 3,3.89 3,5V19A2,2 0 0,0 5,21H19A2,2 0 0,0 21,19V5C21,3.89 20.1,3 19,3Z" />
                             <Setter Property="Opacity" TargetName="Graphic" Value="0.56"/>
-                            <Setter Property="Fill" TargetName="Graphic" Value="{DynamicResource MaterialDesignCheckBoxOff}" />
                         </Trigger>
                     </ControlTemplate.Triggers>
                 </ControlTemplate>