diff --git a/Import/GacUI.cpp b/Import/GacUI.cpp
index 2f87736c..7cf4cd54 100644
--- a/Import/GacUI.cpp
+++ b/Import/GacUI.cpp
@@ -6411,7 +6411,7 @@ GuiControlHost
 						control=control->GetParent();
 					}
 				}
-				return 0;
+				return nullptr;
 			}
 
 			void GuiControlHost::MoveIntoTooltipControl(GuiControl* tooltipControl, Point location)
@@ -6547,7 +6547,15 @@ GuiControlHost
 			void GuiControlHost::Destroying()
 			{
 				WindowDestroying.Execute(GetNotifyEventArguments());
-				SetNativeWindow(0);
+				calledDestroyed = true;
+				if (deleteWhenDestroyed)
+				{
+					GetApplication()->InvokeInMainThread(this, [=]()
+					{
+						delete this;
+					});
+				}
+				SetNativeWindow(nullptr);
 			}
 
 			void GuiControlHost::UpdateClientSizeAfterRendering(Size clientSize)
@@ -6580,6 +6588,20 @@ GuiControlHost
 				delete host;
 			}
 
+			void GuiControlHost::DeleteAfterProcessingAllEvents()
+			{
+				auto window = host->GetNativeWindow();
+				if (calledDestroyed || !window)
+				{
+					delete this;
+				}
+				else
+				{
+					deleteWhenDestroyed = true;
+					GetCurrentController()->WindowService()->DestroyNativeWindow(window);
+				}
+			}
+
 			compositions::GuiGraphicsHost* GuiControlHost::GetGraphicsHost()
 			{
 				return host;
@@ -6902,17 +6924,17 @@ GuiControlHost
 
 			void GuiControlHost::Close()
 			{
-				INativeWindow* window=host->GetNativeWindow();
-				if(window)
+				if (auto window = host->GetNativeWindow())
 				{
-					if(GetCurrentController()->WindowService()->GetMainWindow()!=window)
+					auto mainWindow = GetCurrentController()->WindowService()->GetMainWindow();
+					if (mainWindow == window)
 					{
-						window->Hide(false);
+						SetNativeWindow(nullptr);
+						GetCurrentController()->WindowService()->DestroyNativeWindow(window);
 					}
 					else
 					{
-						SetNativeWindow(0);
-						GetCurrentController()->WindowService()->DestroyNativeWindow(window);
+						window->Hide(false);
 					}
 				}
 			}
@@ -7054,7 +7076,7 @@ GuiWindow
 				INativeWindow* window=host->GetNativeWindow();
 				if(window)
 				{
-					SetNativeWindow(0);
+					SetNativeWindow(nullptr);
 					GetCurrentController()->WindowService()->DestroyNativeWindow(window);
 				}
 			}
@@ -7153,7 +7175,7 @@ GuiWindow
 				ShowModal(owner, [=]()
 				{
 					callback();
-					delete this;
+					DeleteAfterProcessingAllEvents();
 				});
 			}
 
@@ -8599,8 +8621,15 @@ Helper Functions
 
 			void SafeDeleteControl(controls::GuiControl* value)
 			{
-				NotifyFinalizeInstance(value);
-				SafeDeleteControlInternal(value);
+				if (auto controlHost = dynamic_cast<controls::GuiControlHost*>(value))
+				{
+					controlHost->DeleteAfterProcessingAllEvents();
+				}
+				else
+				{
+					NotifyFinalizeInstance(value);
+					SafeDeleteControlInternal(value);
+				}
 			}
 
 			void SafeDeleteComposition(GuiGraphicsComposition* value)
diff --git a/Import/GacUI.h b/Import/GacUI.h
index 7dd2530d..a356d5f0 100644
--- a/Import/GacUI.h
+++ b/Import/GacUI.h
@@ -2218,28 +2218,28 @@ Native Window Services
 			/// Create a window.
 			/// </summary>
 			/// <returns>The created window.</returns>
-			virtual INativeWindow*			CreateNativeWindow()=0;
+			virtual INativeWindow*			CreateNativeWindow() = 0;
 			/// <summary>
 			/// Destroy a window.
 			/// </summary>
 			/// <param name="window">The window to destroy.</param>
-			virtual void					DestroyNativeWindow(INativeWindow* window)=0;
+			virtual void					DestroyNativeWindow(INativeWindow* window) = 0;
 			/// <summary>
 			/// Get the main window.
 			/// </summary>
 			/// <returns>The main window.</returns>
-			virtual INativeWindow*			GetMainWindow()=0;
+			virtual INativeWindow*			GetMainWindow() = 0;
 			/// <summary>
 			/// Get the window that under a specified position in screen space.
 			/// </summary>
 			/// <returns>The window that under a specified position in screen space.</returns>
 			/// <param name="location">The specified position in screen space.</param>
-			virtual INativeWindow*			GetWindow(Point location)=0;
+			virtual INativeWindow*			GetWindow(Point location) = 0;
 			/// <summary>
 			/// Make the specified window a main window, show that window, and wait until the windows is closed.
 			/// </summary>
 			/// <param name="window">The specified window.</param>
-			virtual void					Run(INativeWindow* window)=0;
+			virtual void					Run(INativeWindow* window) = 0;
 		};
 		
 		/// <summary>
@@ -11002,14 +11002,17 @@ Control Host
 				virtual void									OnNativeWindowChanged();
 				virtual void									OnVisualStatusChanged();
 			protected:
-				static const vint								TooltipDelayOpenTime=500;
-				static const vint								TooltipDelayCloseTime=500;
-				static const vint								TooltipDelayLifeTime=5000;
+				static const vint								TooltipDelayOpenTime = 500;
+				static const vint								TooltipDelayCloseTime = 500;
+				static const vint								TooltipDelayLifeTime = 5000;
 
 				Ptr<INativeDelay>								tooltipOpenDelay;
 				Ptr<INativeDelay>								tooltipCloseDelay;
 				Point											tooltipLocation;
 
+				bool											calledDestroyed = false;
+				bool											deleteWhenDestroyed = false;
+
 				controls::GuiControlHost*						GetControlHostForInstance()override;
 				GuiControl*										GetTooltipOwner(Point location);
 				void											MoveIntoTooltipControl(GuiControl* tooltipControl, Point location);
@@ -11051,6 +11054,9 @@ Control Host
 				/// <summary>Window destroying event.</summary>
 				compositions::GuiNotifyEvent					WindowDestroying;
 
+				/// <summary>Delete this control host after processing all events.</summary>
+				void											DeleteAfterProcessingAllEvents();
+
 				/// <summary>Get the internal <see cref="compositions::GuiGraphicsHost"/> object to host the window content.</summary>
 				/// <returns>The internal <see cref="compositions::GuiGraphicsHost"/> object to host the window content.</returns>
 				compositions::GuiGraphicsHost*					GetGraphicsHost();
diff --git a/Import/GacUIReflection.cpp b/Import/GacUIReflection.cpp
index 27f94386..e88e4f93 100644
--- a/Import/GacUIReflection.cpp
+++ b/Import/GacUIReflection.cpp
@@ -2166,6 +2166,7 @@ Type Declaration (Class)
 				CLASS_MEMBER_PROPERTY_FAST(ShortcutKeyManager)
 				CLASS_MEMBER_PROPERTY_READONLY_FAST(RelatedScreen)
 
+				CLASS_MEMBER_METHOD(DeleteAfterProcessingAllEvents, NO_PARAMETER)
 				CLASS_MEMBER_METHOD(ForceCalculateSizeImmediately, NO_PARAMETER)
 				CLASS_MEMBER_METHOD(GetFocused, NO_PARAMETER)
 				CLASS_MEMBER_METHOD(SetFocused, NO_PARAMETER)
diff --git a/Import/GacUIWindows.cpp b/Import/GacUIWindows.cpp
index 8b7fbb16..97d142ec 100644
--- a/Import/GacUIWindows.cpp
+++ b/Import/GacUIWindows.cpp
@@ -13301,30 +13301,22 @@ WindowsForm
 			protected:
 				HWND								handle;
 				WString								title;
-				WindowsCursor*						cursor;
+				WindowsCursor*						cursor = nullptr;
 				Point								caretPoint;
-				WindowsForm*						parentWindow;
-				bool								alwaysPassFocusToParent;
+				WindowsForm*						parentWindow = nullptr;
+				bool								alwaysPassFocusToParent = false;
 				List<INativeWindowListener*>		listeners;
-				vint								mouseLastX;
-				vint								mouseLastY;
-				vint								mouseHoving;
-				Interface*							graphicsHandler;
-				bool								customFrameMode;
+				vint								mouseLastX = -1;
+				vint								mouseLastY = -1;
+				bool								mouseHoving = false;
+				Interface*							graphicsHandler = nullptr;
+				bool								customFrameMode = false;
 				List<Ptr<INativeMessageHandler>>	messageHandlers;
-				bool								supressingAlt;
+				bool								supressingAlt = false;
+				Ptr<bool>							flagDisposed = new bool(false);
 
 			public:
 				WindowsForm(HWND parent, WString className, HINSTANCE hInstance)
-					:cursor(0)
-					,parentWindow(0)
-					,alwaysPassFocusToParent(false)
-					,mouseLastX(-1)
-					,mouseLastY(-1)
-					,mouseHoving(false)
-					,graphicsHandler(0)
-					,customFrameMode(false)
-					,supressingAlt(false)
 				{
 					DWORD exStyle = WS_EX_APPWINDOW | WS_EX_CONTROLPARENT;
 					DWORD style = WS_BORDER | WS_CAPTION | WS_SIZEBOX | WS_SYSMENU | WS_POPUP | WS_CLIPSIBLINGS | WS_CLIPCHILDREN | WS_MAXIMIZEBOX | WS_MINIMIZEBOX;
@@ -13333,12 +13325,13 @@ WindowsForm
 
 				~WindowsForm()
 				{
+					*flagDisposed.Obj() = true;
 					List<INativeWindowListener*> copiedListeners;
 					CopyFrom(copiedListeners, listeners);
-					for(vint i=0;i<copiedListeners.Count();i++)
+					for (vint i = 0; i < copiedListeners.Count(); i++)
 					{
-						INativeWindowListener* listener=copiedListeners[i];
-						if(listeners.Contains(listener))
+						INativeWindowListener* listener = copiedListeners[i];
+						if (listeners.Contains(listener))
 						{
 							listener->Destroyed();
 						}
@@ -13356,11 +13349,14 @@ WindowsForm
 
 				bool HandleMessage(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT& result)
 				{
+#define CHECK_DISPOSED if (*flag.Obj()) return skip
+					auto flag = flagDisposed;
 					bool skip = false;
 					{
 						FOREACH(Ptr<INativeMessageHandler>, handler, messageHandlers)
 						{
 							handler->BeforeHandle(hwnd, uMsg, wParam, lParam, skip);
+							CHECK_DISPOSED;
 						}
 						if (skip)
 						{
@@ -13368,14 +13364,17 @@ WindowsForm
 						}
 					}
 					skip = HandleMessageInternal(hwnd, uMsg, wParam, lParam, result);
+					CHECK_DISPOSED;
 					if (GetWindowsFormFromHandle(hwnd))
 					{
 						FOREACH(Ptr<INativeMessageHandler>, handler, messageHandlers)
 						{
 							handler->AfterHandle(hwnd, uMsg, wParam, lParam, skip, result);
+							CHECK_DISPOSED;
 						}
 					}
 					return skip;
+#undef CHECK_DISPOSED
 				}
 
 				HWND GetWindowHandle()override
@@ -13824,6 +13823,7 @@ WindowsController
 				Dictionary<HWND, WindowsForm*>		windows;
 				INativeWindow*						mainWindow;
 				HWND								mainWindowHandle;
+				vint								handleMessageLevelCounter = 0;
 
 				WindowsCallbackService				callbackService;
 				WindowsResourceService				resourceService;
@@ -13868,51 +13868,59 @@ WindowsController
 				bool HandleMessage(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT& result)
 				{
 					bool skipDefaultProcedure=false;
-					vint index=windows.Keys().IndexOf(hwnd);
-					if(index!=-1)
+					handleMessageLevelCounter++;
 					{
-						WindowsForm* window=windows.Values().Get(index);
-						skipDefaultProcedure=window->HandleMessage(hwnd, uMsg, wParam, lParam, result);
-						switch(uMsg)
+						vint index = windows.Keys().IndexOf(hwnd);
+						if (index != -1)
 						{
-						case WM_CLOSE:
-							if(!skipDefaultProcedure)
+							WindowsForm* window = windows.Values().Get(index);
+							skipDefaultProcedure = window->HandleMessage(hwnd, uMsg, wParam, lParam, result);
+							switch (uMsg)
 							{
-								ShowWindow(window->GetWindowHandle(), SW_HIDE);
-								if(window!=mainWindow)
+							case WM_CLOSE:
+								if (!skipDefaultProcedure)
 								{
-									skipDefaultProcedure=true;
+									ShowWindow(window->GetWindowHandle(), SW_HIDE);
+									if (window != mainWindow)
+									{
+										skipDefaultProcedure = true;
+									}
+								}
+								break;
+							case WM_DESTROY:
+								DestroyNativeWindow(window);
+								break;
+							}
+						}
+					}
+					{
+						if (hwnd == mainWindowHandle && uMsg == WM_DESTROY)
+						{
+							for (vint i = 0; i < windows.Count(); i++)
+							{
+								if (windows.Values().Get(i)->IsVisible())
+								{
+									windows.Values().Get(i)->Hide(true);
 								}
 							}
-							break;
-						case WM_DESTROY:
-							DestroyNativeWindow(window);
-							break;
-						}
-					}
-
-					if(hwnd==mainWindowHandle && uMsg==WM_DESTROY)
-					{
-						for(vint i=0;i<windows.Count();i++)
-						{
-							if(windows.Values().Get(i)->IsVisible())
+							while (windows.Count())
 							{
-								windows.Values().Get(i)->Hide(true);
+								DestroyNativeWindow(windows.Values().Get(0));
 							}
+							PostQuitMessage(0);
 						}
-						while(windows.Count())
-						{
-							DestroyNativeWindow(windows.Values().Get(0));
-						}
-						PostQuitMessage(0);
 					}
-					asyncService.ExecuteAsyncTasks();
+					handleMessageLevelCounter--;
+					if (handleMessageLevelCounter == 0)
+					{
+						asyncService.ExecuteAsyncTasks();
+					}
 					return skipDefaultProcedure;
 				}
 
 				//=======================================================================
 
-				INativeWindow* CreateNativeWindow()
+				INativeWindow* CreateNativeWindow()override
 				{
 					WindowsForm* window=new WindowsForm(godWindow, windowClass.GetName(), hInstance);
 					windows.Add(window->GetWindowHandle(), window);
@@ -13921,7 +13929,7 @@ WindowsController
 					return window;
 				}
 
-				void DestroyNativeWindow(INativeWindow* window)
+				void DestroyNativeWindow(INativeWindow* window)override
 				{
 					WindowsForm* windowsForm=dynamic_cast<WindowsForm*>(window);
 					windowsForm->InvokeDestroying();
@@ -13933,12 +13941,12 @@ WindowsController
 					}
 				}
 
-				INativeWindow* GetMainWindow()
+				INativeWindow* GetMainWindow()override
 				{
 					return mainWindow;
 				}
 
-				void Run(INativeWindow* window)
+				void Run(INativeWindow* window)override
 				{
 					mainWindow=window;
 					mainWindowHandle=GetWindowsForm(window)->GetWindowHandle();
@@ -13952,7 +13960,7 @@ WindowsController
 					}
 				}
 
-				INativeWindow* GetWindow(Point location)
+				INativeWindow* GetWindow(Point location)override
 				{
 					POINT p;
 					p.x=(int)location.x;
diff --git a/Tutorial/GacUI_Controls/AddressBook/UI/Resource.xml b/Tutorial/GacUI_Controls/AddressBook/UI/Resource.xml
index 5a7ed528..4a3cc8e6 100644
--- a/Tutorial/GacUI_Controls/AddressBook/UI/Resource.xml
+++ b/Tutorial/GacUI_Controls/AddressBook/UI/Resource.xml
@@ -305,7 +305,7 @@
           <![CDATA[
             prop FolderName : string = "" {}
             
-            var Ready : bool = true;
+            var Ready : bool = false;
           ]]>
         </ref.Members>
         <Window ref.Name="self" Text="New Folder" ClientSize="x:240 y:120" MaximizedBox="false" MinimizedBox="false" SizeBox="false">