BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Delphi fails to do 'Ondestroy' when shutting down PC          BorlandTalk.com Forum Index -> Delphi Upgrade View previous topic :: View next topic   Author Message Martin Schoellhammer Guest Posted: Fri Feb 06, 2004 11:40 am    Post subject: Delphi fails to do 'Ondestroy' when shutting down PC Hello, I had D4 before and converted an application to D7. The same code behaves other when compiled in D7: I assigned some handling in the 'Ondestroy' event (not only freeing variables) of a form. When I run the app, and then shut down the PC (tested under Win2000) the instructions in the Ondestroy-Event are NOT done, when the app is compiled under D7, in D4 they are. Is there any bugfix or workaround available? Back to top Peter Below (TeamB) Guest Posted: Fri Feb 06, 2004 7:36 pm    Post subject: Re: Delphi fails to do 'Ondestroy' when shutting down PC In article <40236b1b.638908 (AT) newsgroups (DOT) borland.com>, Martin Schoellhammer wrote: Quote: I had D4 before and converted an application to D7. The same code behaves other when compiled in D7: I assigned some handling in the 'Ondestroy' event (not only freeing variables) of a form. When I run the app, and then shut down the PC (tested under Win2000) the instructions in the Ondestroy-Event are NOT done, when the app is compiled under D7, in D4 they are. Highly unlikely IMO. The only form event that fires reliably when you shut down Windows while your app is still running is OnCloseQuery (because it is fired from the WM_QUERYENDSESSION message). No normal application shutdown is performed in this case, none of the apps objects is destroyed in a normal manner since Windows does not bother destroying any Windows when the system goes down. The VCL reacts to the WM_ENDSESSION message (which follows WM_QUERYENDSESSION) by setting Application.Terminated to true. This would make the app exit its message loop and continue with normal closedown (which would indeed destroy the main forms and all other objects owned by the Application object). If it ever woke up again, that is, after receiving the message. And if it had enough time to close down shop before Windows removes the process from memory. Quote: Is there any bugfix or workaround available? Do your state saving in the OnCloseQuery event. -- Peter Below (TeamB) Use the newsgroup archives : http://www.mers.com/searchsite.html http://www.tamaracka.com/search.htm http://groups.google.com http://www.prolix.be Back to top Peter Below (TeamB) Guest Posted: Tue Aug 17, 2004 3:59 pm    Post subject: Re: Delphi fails to do 'Ondestroy' when shutting down PC In article <zenv8buompyn.yz1ddt6jvenk$.dlg (AT) 40tude (DOT) net>, Marcus Mönnig wrote: Quote: I'm doing my cleanup in OnCloseQuery, but I wonder if that is in fact the reason I'm seeing other error messages. Say, I have a TInifile that I create in the OnCreate handler and free in the OnCloseQuery, isn't it possible that even after OnCloseQuery is through, one of the event handlers is called and my code accesses the just freed Tinifile? Yes, that cannot be excluded. Use FreeAndNil to destroy objects, that enables you to check the object variables for Nil before you use them. Or save the state in OnCloseQuery and destroy the objects in OnDestroy. For a TMemInifile saving the state would involve writing any values, then calling the UpdateFile method. For a TInifile you can do the same, although Updatefile will not do anything on WinNT platforms (since inifiles are not buffered by these OSes). Quote: I know you said "do your *state saving* in the OnCloseQuery event" not the cleanup, but for some objects and data structures that is the same. Then separate the two functions. If not possible then take precautions against accessing already deleted objects. -- Peter Below (TeamB) Use the newsgroup archives : http://www.mers.com/searchsite.html http://www.tamaracka.com/search.htm http://groups.google.com http://www.prolix.be Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi Upgrade All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.