程序只允许运行一个实例的三种例子 一：互斥体 program test;uses  Windows; var    MutexHandle: Longword; begin  if OpenMutex(MUTEX_ALL_ACCESS, FALSE, 'test')=0 then  begin    MutexHandle := CreateMutex(nil,TRUE,'test'); //创建一个互斥体，禁止重复运行    MessageBox(0, pchar('try run another?'), pchar('It Works'), 0);    ReleaseMutex(MutexHandle);                                //关闭互斥体  end;end. 异常退出了，互斥体还不消失 二：全局原子 program test; Uses Windows const iAtom=‘SingleApp’; begin　if GlobalFindAtom(iAtom)=0 then　begin　　 GlobalAddAtom(iAtom);        MessageBox(0, pchar('only 1'), pchar('It Works'), 0);　　 GlobalDeleteAtom(GlobalFindAtom(iAtom));　end;end. 三：内存影射 除了能保存全局变量，还可以唯一标志，但异常退出的话也不能消失 program test; Uses Windows var  hMappingFile: THandle;  PShared: ^TShared; begin     hMappingFile := OpenFileMapping(FILE_MAP_READ, False, 'test');     if hMappingFile = 0 then     begin        hMappingFile := CreateFileMapping($FFFFFFFF, nil, PAGE_READWRITE, 0, SizeOf(TShared), 'test');        PShared := MapViewOfFile(hMappingFile, FILE_MAP_WRITE or FILE_MAP_READ, 0, 0, 0);        MessageBox(0, pchar('the one'), pchar('It Works'), 0);          UnmapViewOfFile(PShared);       CloseHandle(hMappingFile);　 end;end.  

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