onlyoneinst.cpp

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// OnlyOneInst.cpp : Defines the class behaviors for the application.
//

#include "stdafx.h"
#include "OnlyOneInst.h"
#include "OnlyOneInstDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// COnlyOneInstApp

BEGIN_MESSAGE_MAP(COnlyOneInstApp, CWinApp)
	//{{AFX_MSG_MAP(COnlyOneInstApp)
		// NOTE - the ClassWizard will add and remove mapping macros here.
		//    DO NOT EDIT what you see in these blocks of generated code!
	//}}AFX_MSG
	ON_COMMAND(ID_HELP, CWinApp::OnHelp)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// COnlyOneInstApp construction

COnlyOneInstApp::COnlyOneInstApp()
{
	// TODO: add construction code here,
	// Place all significant initialization in InitInstance
}

/////////////////////////////////////////////////////////////////////////////
// The one and only COnlyOneInstApp object

COnlyOneInstApp theApp;

/////////////////////////////////////////////////////////////////////////////
// COnlyOneInstApp initialization

BOOL COnlyOneInstApp::InitInstance()
{
	if (!FirstInstance())
		return FALSE;	//已经有实例存在了，退出
	AfxEnableControlContainer();

	// Standard initialization
	// If you are not using these features and wish to reduce the size
	//  of your final executable, you should remove from the following
	//  the specific initialization routines you do not need.

#ifdef _AFXDLL
	Enable3dControls();			// Call this when using MFC in a shared DLL
#else
	Enable3dControlsStatic();	// Call this when linking to MFC statically
#endif

	COnlyOneInstDlg dlg;
	m_pMainWnd = &dlg;
	int nResponse = dlg.DoModal();
	if (nResponse == IDOK)
	{
		// TODO: Place code here to handle when the dialog is
		//  dismissed with OK
	}
	else if (nResponse == IDCANCEL)
	{
		// TODO: Place code here to handle when the dialog is
		//  dismissed with Cancel
	}

	// Since the dialog has been closed, return FALSE so that we exit the
	//  application, rather than start the application's message pump.
	return FALSE;
}
BOOL COnlyOneInstApp::FirstInstance()
{
  CWnd *pWndPrev, *pWndChild;
  
  //根据主窗口类名和主窗口名判断是否已经有实例存在了
  if (pWndPrev = CWnd::FindWindow(_T("#32770"),"OnlyOne"))
  {//如果存在就将其激活，并显示出来
	  
	  pWndChild = pWndPrev->GetLastActivePopup(); 
	  
	  //如果是最小化的就还原窗口
	  if (pWndPrev->IsIconic()) 
		  pWndPrev->ShowWindow(SW_RESTORE);      
	  
	  pWndChild->SetForegroundWindow();         
	 
	  return FALSE;                             
  }
  else
	  return TRUE;                             
}