fixed Background of ComboBox when disabled

Author: corvinsz

src/MainDemo.Wpf/FieldsLineUp.xaml.cs

@@ -56,6 +56,7 @@ public FieldsLineUp()
                 tb.SetBinding(TextBoxBase.IsReadOnlyProperty, new Binding(nameof(CheckBox.IsChecked)) { ElementName = nameof(IsReadOnlyCheckBox) });
             SetValue(control);
         }
+        IsEnabledCheckBox.IsChecked = false;
     }
 
     private void UpdateThickness(RangeBase slider, DependencyProperty property, bool horizontal)

src/MainDemo.Wpf/Properties/launchSettings.json

@@ -2,7 +2,7 @@
     "profiles": {
         "Demo App": {
             "commandName": "Project",
-            "commandLineArgs": "-p Home -t Inherit -f LeftToRight"
+            "commandLineArgs": "-p \"Fields line up\" -t Light -f LeftToRight"
         }
     }
 }

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

@@ -627,7 +627,7 @@
           <Condition Property="wpf:TextFieldAssist.HasOutlinedTextField" Value="False" />
         </MultiTrigger.Conditions>
         <Setter TargetName="OuterBorder" Property="BorderBrush" Value="Transparent" />
-        <Setter TargetName="OuterBorder" Property="Opacity" Value="{x:Static wpf:Constants.TextBoxNotEnabledOpacity}" />
+        <Setter TargetName="ContentGrid" Property="Opacity" Value="{x:Static wpf:Constants.TextBoxNotEnabledOpacity}" />
         <Setter TargetName="OuterBorder" Property="wpf:BottomDashedLineAdorner.IsAttached" Value="True" />
         <Setter TargetName="OuterBorder" Property="wpf:BottomDashedLineAdorner.DashStyle" Value="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(wpf:TextFieldAssist.HasFilledTextField), Converter={StaticResource BooleanToDashStyleConverter}}" />
         <Setter TargetName="toggleButton" Property="Opacity" Value="1" />