检查应用程序是否存在已在运行的实例

检查应用程序是否存在已经在运行的实例，如果有则强制终止之。

HANDLE GetPrevInstance()
{
	HANDLE snapshot;
	PROCESSENTRY32 processInfo;
	
	processInfo.dwSize = sizeof(processInfo);

	snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

	if (snapshot == NULL) return;

	bool flag = Process32First(snapshot, &processInfo);

	while(flag)
	{
		if (!_tcsncmp(processInfo.szExeFile, CON_MAINEXE, _tcslen(CON_MAINEXE)) && processInfo.th32ProcessID != GetCurrentProcessId())
		{
			return OpenProcess(PROCESS_ALL_ACCESS, FALSE, processInfo.th32ProcessID);						
		}
		
		flag = Process32Next(snapshot,&processInfo);
	}

	return NULL;

	CloseToolhelp32Snapshot(&snapshot);

}


BOOL SetPrivilege(HANDLEhToken, LPCTSTR lpszPrivilege, BOOL bEnablePrivilege)
{
	TOKEN_PRIVILEGES tp;
	LUID luid;
	int error = 0;

	if (!LookupPrivilegeValue(NULL, lpszPrivilege, &luid))
	{
		error = GetLastError();
		//::MessageBox(NULL, NULL, "\nLookupPrivilegeValue error:%d", GetLastError(), 0);
		return FALSE;
	}

	tp.PrivilegeCount = 1;
	tp.Privileges[0].Luid=luid;
	tp.Privileges[0].Attributes = bEnablePrivilege ? SE_PRIVILEGE_ENABLED : 0;

	AdjustTokenPrivileges(hToken, FALSE, &tp, sizeof(TOKEN_PRIVILEGES), NULL, NULL);

	if(GetLastError() != ERROR_SUCCESS)
	{
		error = GetLastError();
		return FALSE;
	}
	returnTRUE;
}


void CheckPrevInstance()
{
	HANDLE hProcess = NULL;
	DWORD count = 0;
	int error = 0;

	while ((hProcess = GetPrevInstance()))
	{
		sleep(200);
		count ++;

		if (count >= 10)
		{
			if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &hProcessToken))
			{
				error = GetLastError();
				return;
			}

			if (!SetPrivilege(hProcessToken, SE_DEBUG_NAME, TRUE))
			{
				error = GetLastError();
				return;
			}
    
			TerminateProcess(hProcess, 1);			
			CloseHandle(hProcess);
			break;
		}

		CloseHandle(hProcess);
	}
}