Disable Acrylic while Moving or Resizing Window

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

@@ -1,4 +1,6 @@
-using System.Runtime.InteropServices;
+using System;
+using System.Runtime.InteropServices;
+using System.Windows.Interop;
 using HandyControl.Data;
 using HandyControl.Tools;
 using HandyControl.Tools.Helper;
@@ -8,13 +10,41 @@ namespace HandyControl.Controls
 {
     public class BlurWindow : Window
     {
+        private static readonly int WM_EXITSIZEMOVE = 0x0232;
+        private static readonly int WM_ENTERSIZEMOVE = 0x0231;
+
+        public BlurWindow()
+        {
+            var versionInfo = SystemHelper.GetSystemVersionInfo();
+
+            if (versionInfo >= SystemVersionInfo.Windows10_1903)
+            {
+                var source = HwndSource.FromHwnd(WindowHelper.GetHandle(this));
+                source.AddHook(WndProc);
+            }
+        }
+
+        private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
+        {
+            if (msg == WM_ENTERSIZEMOVE)
+            {
+                EnableBlur(this, false);
+            }
+            else if (msg == WM_EXITSIZEMOVE)
+            {
+                EnableBlur(this);
+            }
+
+            return IntPtr.Zero;
+        }
+
         public override void OnApplyTemplate()
         {
             base.OnApplyTemplate();
             EnableBlur(this);
         }
 
-        internal static void EnableBlur(Window window)
+        internal static void EnableBlur(Window window, bool isEnabled = true)
         {
             var versionInfo = SystemHelper.GetSystemVersionInfo();
 
@@ -23,21 +53,24 @@ namespace HandyControl.Controls
 
             accentPolicy.AccentFlags = 2;
 
-            if (versionInfo >= SystemVersionInfo.Windows10_1903)
+            if (isEnabled)
             {
-                accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_BLURBEHIND;
-            }
-            else if (versionInfo >= SystemVersionInfo.Windows10_1809)
-            {
-                accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_ACRYLICBLURBEHIND;
-            }
-            else if (versionInfo >= SystemVersionInfo.Windows10)
-            {
-                accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_BLURBEHIND;
+                if (versionInfo >= SystemVersionInfo.Windows10_1809)
+                {
+                    accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_ACRYLICBLURBEHIND;
+                }
+                else if (versionInfo >= SystemVersionInfo.Windows10)
+                {
+                    accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_BLURBEHIND;
+                }
+                else
+                {
+                    accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_TRANSPARENTGRADIENT;
+                }
             }
             else
             {
-                accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_TRANSPARENTGRADIENT;
+                accentPolicy.AccentState = InteropValues.ACCENTSTATE.ACCENT_ENABLE_BLURBEHIND;
             }
 
             accentPolicy.GradientColor = ResourceHelper.GetResource<uint>(ResourceToken.BlurGradientValue);