38 lines
944 B
C++
38 lines
944 B
C++
#ifndef LimitSingleInstance_H
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#define LimitSingleInstance_H
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#include <windows.h>
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//this code is from Q243953 in case you lose the article and wonder
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//where this code came from...
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class CLimitSingleInstance
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{
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protected:
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DWORD m_dwLastError;
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HANDLE m_hMutex;
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public:
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CLimitSingleInstance(TCHAR *strMutexName)
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{
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//be sure to use a name that is unique for this application otherwise
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//two apps may think they are the same if they are using same name for
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//3rd parm to CreateMutex
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m_hMutex = CreateMutex(NULL, FALSE, strMutexName); //do early
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m_dwLastError = GetLastError(); //save for use later...
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}
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~CLimitSingleInstance()
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{
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if (m_hMutex) //don't forget to close handles...
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{
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CloseHandle(m_hMutex); //do as late as possible
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m_hMutex = NULL; //good habit to be in
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}
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}
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BOOL IsAnotherInstanceRunning()
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{
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return (ERROR_ALREADY_EXISTS == m_dwLastError);
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}
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};
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#endif |