support for sync with system theme

src/Net_40/HandyControl_Net_40/Themes/Theme.xaml

@@ -11752,7 +11752,7 @@
 		<Setter Property="Focusable" Value="False" />
 		<Setter Property="MinHeight" Value="60" />
 		<Setter Property="Width" Value="320" />
-		<Setter Property="Margin" Value="10,0,0,10" />
+		<Setter Property="Margin" Value="10,10,10,0" />
 		<Setter Property="MaxWidth" Value="320" />
 		<Setter Property="hc:BorderElement.CornerRadius" Value="8" />
 		<Setter Property="Background" Value="{DynamicResource ThirdlyRegionBrush}" />

src/Shared/HandyControl_Shared/Controls/Attach/DataGridAttach.cs

@@ -337,7 +337,7 @@ namespace HandyControl.Controls
         }
 
         public static void SetCanUnselectAllWithBlankArea(DependencyObject element, bool value)
-            => element.SetValue(CanUnselectAllWithBlankAreaProperty, value);
+            => element.SetValue(CanUnselectAllWithBlankAreaProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetCanUnselectAllWithBlankArea(DependencyObject element)
             => (bool) element.GetValue(CanUnselectAllWithBlankAreaProperty);

src/Shared/HandyControl_Shared/Controls/Attach/DropDownElement.cs

@@ -20,7 +20,7 @@ namespace HandyControl.Controls
             new FrameworkPropertyMetadata(ValueBoxes.FalseBox, FrameworkPropertyMetadataOptions.Inherits));
 
         public static void SetAutoWidth(DependencyObject element, bool value)
-            => element.SetValue(AutoWidthProperty, value);
+            => element.SetValue(AutoWidthProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetAutoWidth(DependencyObject element)
             => (bool) element.GetValue(AutoWidthProperty);

src/Shared/HandyControl_Shared/Controls/Attach/WindowAttach.cs

@@ -141,7 +141,7 @@ namespace HandyControl.Controls
         }
 
         public static void SetHideWhenClosing(DependencyObject element, bool value)
-            => element.SetValue(HideWhenClosingProperty, value);
+            => element.SetValue(HideWhenClosingProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetHideWhenClosing(DependencyObject element)
             => (bool) element.GetValue(HideWhenClosingProperty);

src/Shared/HandyControl_Shared/Controls/Other/Empty.cs

@@ -28,7 +28,7 @@ namespace HandyControl.Controls
             "ShowEmpty", typeof(bool), typeof(Empty), new FrameworkPropertyMetadata(ValueBoxes.FalseBox, FrameworkPropertyMetadataOptions.Inherits));
 
         public static void SetShowEmpty(DependencyObject element, bool value)
-            => element.SetValue(ShowEmptyProperty, value);
+            => element.SetValue(ShowEmptyProperty, ValueBoxes.BooleanBox(value));
 
         public static bool GetShowEmpty(DependencyObject element)
             => (bool) element.GetValue(ShowEmptyProperty);

src/Shared/HandyControl_Shared/Controls/Window/BlurWindow.cs

@@ -2,6 +2,7 @@
 using System.Windows.Media;
 using HandyControl.Data;
 using HandyControl.Tools;
+using HandyControl.Tools.Helper;
 using HandyControl.Tools.Interop;
 
 namespace HandyControl.Controls
@@ -14,17 +15,9 @@ namespace HandyControl.Controls
             EnableBlur(this);
         }
 
-        private static SystemVersionInfo GetSystemVersionInfo()
-        {
-            var osv = new InteropValues.RTL_OSVERSIONINFOEX();
-            osv.dwOSVersionInfoSize = (uint) Marshal.SizeOf(osv);
-            InteropMethods.Gdip.RtlGetVersion(out osv);
-            return new SystemVersionInfo((int) osv.dwMajorVersion, (int) osv.dwMinorVersion, (int) osv.dwBuildNumber);
-        }
-
         internal static void EnableBlur(Window window)
         {
-            var versionInfo = GetSystemVersionInfo();
+            var versionInfo = SystemHelper.GetSystemVersionInfo();
 
             if (versionInfo < SystemVersionInfo.Windows10 ||
                 versionInfo >= SystemVersionInfo.Windows10_1903)

src/Shared/HandyControl_Shared/HandyControl_Shared.projitems

@@ -372,6 +372,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\ScreenHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\SecurityHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\SingleOpenHelper.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\SystemHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\TextHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\TokenizerHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Tools\Helper\TouchDragMoveWindowHelper.cs" />

src/Shared/HandyControl_Shared/Themes/Theme.cs

@@ -1,8 +1,10 @@
 using System;
-using System.Linq;
+using System.Collections.Generic;
 using System.Windows;
 using HandyControl.Data;
 using HandyControl.Tools;
+using HandyControl.Tools.Helper;
+using Microsoft.Win32;
 
 namespace HandyControl.Themes
 {
@@ -12,14 +14,8 @@ namespace HandyControl.Themes
         {
             if (DesignerHelper.IsInDesignMode)
             {
-                MergedDictionaries.Add(new()
-                {
-                    Source = new Uri("pack://application:,,,/HandyControl;component/Themes/SkinDefault.xaml")
-                });
-                MergedDictionaries.Add(new()
-                {
-                    Source = new Uri("pack://application:,,,/HandyControl;component/Themes/Theme.xaml")
-                });
+                MergedDictionaries.Add(ResourceHelper.GetSkin(SkinType.Default));
+                MergedDictionaries.Add(ResourceHelper.GetTheme());
             }
             else
             {
@@ -35,6 +31,8 @@ namespace HandyControl.Themes
             set => _source = value;
         }
 
+        private SkinType _manualSkinType;
+
         private SkinType _skin;
 
         public virtual SkinType Skin
@@ -54,32 +52,43 @@ namespace HandyControl.Themes
 
         private static void OnSkinChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
-            if (d is FrameworkElement element)
+            if (d is not FrameworkElement element)
             {
-                var skin = (SkinType) e.NewValue;
+                return;
+            }
 
-                if (element.Resources is Theme resource)
+            var skin = (SkinType) e.NewValue;
+
+            var themes = new List<Theme>();
+            GetAllThemes(element.Resources, ref themes);
+
+            if (themes.Count > 0)
+            {
+                foreach (var theme in themes)
                 {
-                    resource.Skin = skin;
+                    theme.Skin = skin;
                 }
-                else
+            }
+            else
+            {
+                element.Resources.MergedDictionaries.Add(new Theme
                 {
-                    var themes = element.Resources.MergedDictionaries.OfType<Theme>();
-                    if (!themes.Any())
-                    {
-                        element.Resources.MergedDictionaries.Add(new Theme
-                        {
-                            Skin = skin
-                        });
-                    }
-                    else
-                    {
-                        foreach (var subResource in element.Resources.MergedDictionaries.OfType<Theme>())
-                        {
-                            subResource.Skin = skin;
-                        }
-                    }
-                }
+                    Skin = skin
+                });
+            }
+        }
+
+        private static void GetAllThemes(ResourceDictionary resourceDictionary, ref List<Theme> themes)
+        {
+            if (resourceDictionary is Theme theme)
+            {
+                themes.Add(theme);
+            }
+
+            // we must consider it's MergedDictionaries
+            foreach (var dictionaryMergedDictionary in resourceDictionary.MergedDictionaries)
+            {
+                GetAllThemes(dictionaryMergedDictionary, ref themes);
             }
         }
 
@@ -89,6 +98,39 @@ namespace HandyControl.Themes
         public static SkinType GetSkin(DependencyObject element)
             => (SkinType) element.GetValue(SkinProperty);
 
+        private bool _syncWithSystem;
+
+        public bool SyncWithSystem
+        {
+            get => _syncWithSystem;
+            set
+            {
+                _syncWithSystem = value;
+
+                if (value)
+                {
+                    _manualSkinType = Skin;
+                    SyncWithSystemTheme();
+                    SystemEvents.UserPreferenceChanged += SystemEvents_UserPreferenceChanged;
+                }
+                else
+                {
+                    SystemEvents.UserPreferenceChanged -= SystemEvents_UserPreferenceChanged;
+                    Skin = _manualSkinType;
+                }
+            }
+        }
+
+        private void SystemEvents_UserPreferenceChanged(object sender, UserPreferenceChangedEventArgs e)
+        {
+            if (e.Category == UserPreferenceCategory.General)
+            {
+                SyncWithSystemTheme();
+            }
+        }
+
+        private void SyncWithSystemTheme() => Skin = SystemHelper.DetermineIfInLightThemeMode() ? SkinType.Default : SkinType.Dark;
+
         public string Name { get; set; }
 
         public virtual ResourceDictionary GetSkin(SkinType skinType) => ResourceHelper.GetSkin(skinType);

src/Shared/HandyControl_Shared/Tools/Helper/ResourceHelper.cs

@@ -54,7 +54,7 @@ namespace HandyControl.Tools
         {
             try
             {
-                var uri = new Uri($"pack://application:,,,/{assembly.GetName().Name};component/{themePath}/Skin{skin.ToString()}.xaml");
+                var uri = new Uri($"pack://application:,,,/{assembly.GetName().Name};component/{themePath}/Skin{skin}.xaml");
                 return new ResourceDictionary
                 {
                     Source = uri
@@ -64,7 +64,7 @@ namespace HandyControl.Tools
             {
                 return new ResourceDictionary
                 {
-                    Source = new Uri($"pack://application:,,,/{assembly.GetName().Name};component/{themePath}/Skin{SkinType.Default.ToString()}.xaml")
+                    Source = new Uri($"pack://application:,,,/{assembly.GetName().Name};component/{themePath}/Skin{SkinType.Default}.xaml")
                 };
             }
         }

src/Shared/HandyControl_Shared/Tools/Helper/SystemHelper.cs

@@ -0,0 +1,29 @@
+using System.Runtime.InteropServices;
+using HandyControl.Data;
+using HandyControl.Tools.Interop;
+using Microsoft.Win32;
+
+namespace HandyControl.Tools.Helper
+{
+    internal class SystemHelper
+    {
+        public static SystemVersionInfo GetSystemVersionInfo()
+        {
+            var osv = new InteropValues.RTL_OSVERSIONINFOEX();
+            osv.dwOSVersionInfoSize = (uint) Marshal.SizeOf(osv);
+            InteropMethods.Gdip.RtlGetVersion(out osv);
+            return new SystemVersionInfo((int) osv.dwMajorVersion, (int) osv.dwMinorVersion, (int) osv.dwBuildNumber);
+        }
+
+        private const string SkinTypeRegistryKeyName = @"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize";
+
+        private const string SkinTypeRegistryValueName = "AppsUseLightTheme";
+
+        public static bool DetermineIfInLightThemeMode()
+        {
+            var value = Registry.GetValue(SkinTypeRegistryKeyName, SkinTypeRegistryValueName, "0");
+
+            return value != null && value.ToString() != "0";
+        }
+    }
+}