Par2: Check for multiple instances of a program 1998-04-22 -- Jeff Berlinghoff After Global INCLUDEs:
ERROR_ALREADY_EXISTS EQUATE(183)
SECURITY_ATTRIBUTES GROUP,TYPE
nLength ULONG
lpSecurityDescriptor ULONG
bInheritHandle BOOL
END
Inside the Global Map:
MODULE('Kernal32')
CreateSemaphore(<*SECURITY_ATTRIBUTES lpSemaphoreAttributes>, LONG
lInitialCount, LONG lMaximumCount, *CSTRING
lpName),LONG,RAW,PASCAL,NAME('CreateSemaphoreA')
CloseHandle(LONG hObject),BOOL,PASCAL
GetLastError(),ULONG,PASCAL
FindWindow(<*CSTRING lpClassName>, *CSTRING
lpWindowName),UNSIGNED,PASCAL,RAW,NAME('FindWindowA')
SetWindowText(UNSIGNED,*CSTRING),PASCAL,RAW,NAME('SetWindowTextA')
IsIconic(UNSIGNED),BOOL,PASCAL
ShowWindow(UNSIGNED, SIGNED nCmdShow),BOOL,PASCAL
SetForegroundWindow(UNSIGNED),BOOL,PASCAL
END
On your FRAME, After Opening the Window:
IF ~StartNewAppInstance(0{prop:text}) THEN RETURN.
Create New Procedure named StartNewAppInstance
Prototype: (STRING),SHORT
Parameters: (WndTitle)
Data Section:
RetVal SHORT(True)
cTitle CSTRING(255)
cTemp CSTRING(255)
SemName CSTRING(255)
hSem LONG
hMe LONG
Processed Code:
SemName = 'Semaphore Name'
cTitle = WndTitle
hSem = CreateSemaphore(, 0, 1, SemName)
IF hSem AND (GetLastError() = ERROR_ALREADY_EXISTS)
n#=CloseHandle(hSem)
hMe = FindWindow(, cTitle) !rename new instance so we can find another
cTemp='Terminating Duplicate Instance'; SetWindowText(hMe, cTemp)
hMe = FindWindow(, cTitle)
IF hMe
IF IsIconic(hMe) THEN n#=ShowWindow(hMe, 1) ELSE
n#=SetForegroundWindow(hMe).
RetVal=False !Cannot start a new instance, use already running instance
END
END
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