//File Name: Singleton.h #pragma once class Singleton { private:     CString strGUID;     CString strMapFileGUID;     HANDLE m_hSingleton; public:     Singleton();     ~Singleton(); public:     void AppStart (const HWND & hWnd) const; };

//File Name: Singleton.cpp #include "stdafx.h" #include "Singleton.h" Singleton::Singleton() {     strGUID = _T("{D727BDB5-F86A-405b-910D-11AD2A4CA76E}");     strMapFileGUID = strGUID + _T("_MapFile");     m_hSingleton = NULL; } Singleton::~Singleton() {     if (m_hSingleton)     {         CloseHandle(m_hSingleton);         m_hSingleton = NULL;     } } void Singleton::AppStart(const HWND & hWnd) const {     HANDLE m_hSingleton = NULL;     m_hSingleton = CreateMutex(NULL, TRUE, strGUID);     RECT rect;     ZeroMemory(&rect, sizeof(rect));     ::GetWindowRect(hWnd, &rect);     if (GetLastError() == ERROR_ALREADY_EXISTS)     {         // 打开共享文件         HANDLE hHandle = ::OpenFileMapping(FILE_MAP_ALL_ACCESS, FALSE, strMapFileGUID);         if (hHandle)         {             LPTSTR lpMapAddr = (LPTSTR)::MapViewOfFile(hHandle, FILE_MAP_ALL_ACCESS, 0, 0, 0);             CString strBuffer(lpMapAddr);             HWND hOldWnd = (HWND)_tcstoul(strBuffer, NULL, 10);             ::SetForegroundWindow(hOldWnd);             // 取消内核对象的映射             UnmapViewOfFile(hHandle);             CloseHandle(hHandle);             exit(0);         }     }     else        // 第一运行程序     {         int nNum = sizeof(HANDLE);         // 创建文件映射内核对象         HANDLE hHandle = ::CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, sizeof(HANDLE), strMapFileGUID);         if (hHandle)         {             // 拷贝数据到共享文件里             LPTSTR lpMapAddr = (LPTSTR)::MapViewOfFile(hHandle, FILE_MAP_ALL_ACCESS, 0, 0, 0);             CString strBuffer;             strBuffer.Format(_T("%d"), hWnd);             _tcscpy(lpMapAddr, strBuffer);             // 讲写入文件映射缓冲区的所有数据刷新到磁盘；             ::FlushViewOfFile(lpMapAddr, strBuffer.GetLength()+1);         }     } }