🚀 go-pugleaf

"luca casotti" <lucacasotti@libero.it> ha scritto nel messaggio 
news:4190b40a$1@newsgroups.borland.com...
> when a process starts, how can it know if there is another his instance
> already running?
>
>


FAQ3816C.txt   Preventing multiple instances with BCB

            Category   :Windows API

            Product    :   All32Bit



            Question:

            I want to permit only one copy of my program to run at a time. 
The Previous

            Instance is always set to NULL, yet it is supposed to be NULL 
only the first

            time you run the program.



            Answer:

            This is a code example of using a Mutex to determine if another

            instance is running.



            ::CreateMutex(NULL, FALSE, "YourMutexName");

                if ( GetlastError() == ERROR_ALREADY_EXISTS )

                {

                    // Found another running application with the same mutex

                    // so one instance is already running.

                    Application->Title="Testing";  // prohibits finding this 
instance

                    HWND FirsthWnd, FirstChildhWnd;

                    // see Application->Title or Options|Project|Application 
Tab|Title

                    FirsthWnd = ::FindWindow("TApplication", 
"YourApplicationTitle");

                    if (::IsIconic(FirsthWnd))

                        ::ShowWindow(FirsthWnd, SW_SHOWDEFAULT);

                    ::SetForegroundWindow(FirsthWnd);

                    FirstChildhWnd = ::GetLastActivePopup(FirsthWnd);

                    if (FirsthWnd != FirstChildhWnd)

                        ::BringWindowToTop(FirstChildhWnd); // A pop-up is 
active so bring it to the top too.

                }

                else

                {

                    Application->Initialize();

                    Application->Title = "YourApplicationTitle";

                    Application->CreateForm(__classid(TYourAppMainForm),&YourAppMainForm);

                }


Good Luck
Paolo Borlandi