使用命名对象防止运行一个程序的多个实例

1.要点

• 在程序的入口处调用CreateXXX函数创建一个命名对象（如Mutex,Event等均可），然后调用GetLastError()函数检查返回值，看此对象是否已存在，如果已存在则说明已存在此程序的实例
• 在程序的出口点调用CloseHandle()关闭在入口处创建的命名对象

2.实现代码

  1: //At the entry point, such aa the beginning of WinMain in Win32 app,
  2: //or CWinApp::InitInstance() in MFC app
  3: LPCTSTR instanceName = 
  4:      _T("AD83912A-43F2-4BF6-B0CF-02BF6589FFF7");  //Generated with GuidGen tool
  5: HANDLE h = ::CreateMutex(NULL,FALSE,instanceName);
  6: DWORD error = GetLastError();
  7: if (error == ERROR_ALREADY_EXISTS)
  8: {
  9: 	::CloseHandle(h);
 10: 	return FALSE;  //Exist
 11: }
 12: 
 13: //.......
 14: 
 15: //At the exist point, close the named object and then exist
 16: ::CloseHandle(h);
 17: return FALSE; //Exist
 18: