fixed #675

src/Shared/HandyControl_Shared/Controls/Growl/GrowlWindow.cs

@@ -1,5 +1,8 @@
-using System.Windows;
+using System;
+using System.Windows;
 using System.Windows.Controls;
+using HandyControl.Tools;
+using HandyControl.Tools.Interop;
 
 namespace HandyControl.Controls
 {
@@ -33,5 +36,8 @@ namespace HandyControl.Controls
             Left = desktopWorkingArea.Right - Width;
             Top = 0;
         }
+
+        protected override void OnSourceInitialized(EventArgs e)
+            => InteropMethods.IntDestroyMenu(this.GetHwndSource().CreateHandleRef());
     }
 }

src/Shared/HandyControl_Shared/Tools/Interop/InteropMethods.cs

@@ -97,6 +97,10 @@ namespace HandyControl.Tools.Interop
         [DllImport(InteropValues.ExternDll.User32)]
         internal static extern bool InsertMenu(IntPtr hMenu, int wPosition, int wFlags, int wIDNewItem, string lpNewItem);
 
+        [DllImport(InteropValues.ExternDll.User32, ExactSpelling = true, EntryPoint = "DestroyMenu", CharSet = CharSet.Auto)]
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern bool IntDestroyMenu(HandleRef hMenu);
+
         [SecurityCritical]
         [SuppressUnmanagedCodeSecurity]
         [DllImport(InteropValues.ExternDll.User32, SetLastError = true, ExactSpelling = true, EntryPoint = nameof(GetDC),