单实例

  1 #pragma once
  2 
  3 #define UM_ACTIVATE (WM_USER + 0x2001)
  4 #define SINGLE_STRING (TEXT( "0x13cc6a4e, 0x2e3a, 0x46fa, 0x9d, 0x60, 0x43, 0x85, 0x71, 0x64, 0xd0, 0x28" ))
  5 
  6 class CSingleSign
  7 {
  8     HANDLE m_hMutex;
  9 public:
 10     CSingleSign()
 11     {
 12         HWND hWndPrevious;
 13 
 14         m_hMutex = ::CreateMutex( NULL, FALSE, SINGLE_STRING );
 15         if ( GetLastError() == ERROR_ALREADY_EXISTS )
 16         {
 17             hWndPrevious = ::GetWindow( ::GetDesktopWindow(), GW_CHILD );
 18             while ( ::IsWindow( hWndPrevious ) )
 19             {
 20                 if ( ::GetProp( hWndPrevious, SINGLE_STRING ) )
 21                 {
 22                     ::PostMessage( hWndPrevious, UM_ACTIVATE, ( WPARAM )0, ( LPARAM )0 );
 23                     break;
 24                 }
 25 
 26                 hWndPrevious = ::GetWindow( hWndPrevious, GW_HWNDNEXT );
 27             }
 28 
 29             exit( 0 );
 30         }
 31 
 32         if ( m_hMutex == NULL )
 33         {
 34             exit( 0 );
 35         }
 36     }
 37 
 38     ~CSingleSign()
 39     {
 40         ::CloseHandle( m_hMutex );
 41     }
 42 };
 43 
 44 
 45 template <typename T>
 46 class ATL_NO_VTABLE CSingleApp
 47 {
 48     static CSingleSign _m_SingleSign;
 49 public:
 50     CSingleApp(){_m_SingleSign;}
 51 
 52     BEGIN_MSG_MAP( CSingleApp<T> )
 53         MESSAGE_HANDLER( WM_CREATE, OnInitializeIt )
 54         MESSAGE_HANDLER( WM_INITDIALOG, OnInitializeIt )
 55         MESSAGE_HANDLER( WM_DESTROY, OnDestroy )
 56         MESSAGE_HANDLER( UM_ACTIVATE, OnActive )
 57     END_MSG_MAP()
 58 
 59     
 60     LRESULT OnInitializeIt( UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled )
 61     {
 62         LRESULT lRet;
 63         T* pT = static_cast<T*>( this );
 64 
 65         lRet = pT->InitializeIt( uMsg, wParam, lParam, bHandled );
 66 
 67         ::SetProp( pT->m_hWnd, SINGLE_STRING, ( HANDLE )1 );
 68 
 69         return lRet;
 70     }
 71 
 72     LRESULT OnDestroy( UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled )
 73     {
 74         T* pT = static_cast<T*>( this );
 75 
 76         ::RemoveProp( pT->m_hWnd, SINGLE_STRING );
 77 
 78         return pT->DestroyIt( uMsg, wParam, lParam, bHandled );
 79     }
 80 
 81 
 82     LRESULT OnActive( UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& bHandled )
 83     {
 84         T* pT = static_cast<T*>( this );
 85 
 86         if ( pT->IsIconic() )
 87         {
 88             pT->ShowWindow( SW_RESTORE );
 89         }
 90         else
 91         {
 92             if ( !pT->IsWindowVisible() )
 93             {
 94                 pT->ShowWindow( SW_SHOW );
 95                 ::BringWindowToTop( pT->m_hWnd );
 96             }
 97 
 98             ::SetForegroundWindow( pT->m_hWnd );
 99         }
100 
101         bHandled = TRUE;
102         return 0;
103     }
104 };
105 
106 
107 template<typename T>
108 CSingleSign CSingleApp<T>::_m_SingleSign;