support for sync with system theme

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";
+        }
+    }
+}