#include "stdafx.h"
#include "SingleInstance.h"

CSingleInstance::CSingleInstance()

{

	// Set our default values

	m_hMutex = NULL;

}



CSingleInstance::~CSingleInstance()

{

	if ( m_hMutex != NULL ) {

		ReleaseMutex( m_hMutex );

	}

}



BOOL CSingleInstance::Create(LPCSTR pszClassName)

{

	// Add the word 'Class' to the end

	m_strClassName = pszClassName;



	// Create the mutex

	m_hMutex = CreateMutex( NULL, FALSE, m_strClassName );
	//m_hMutex = CreateSemaphore(NULL, 1, 1, m_strClassName);
	// Check for errors

	if ( GetLastError() == ERROR_ALREADY_EXISTS ) {

		m_hMutex = NULL;
		CString s;
		// 尋找先前實例的主窗口 
		HWND hWndPrevious = ::GetWindow(::GetDesktopWindow(),GW_CHILD); 
		while (::IsWindow(hWndPrevious)) 
		{ 
			// 檢查窗口是否有預設的標記? 
			// 有，則是我們尋找的主窗 
			::GetWindowText(hWndPrevious,(char*)(LPCTSTR)s ,255);
			if (!s.Find(m_strClassName)) 
			{ 
				ShowWindow(hWndPrevious,SW_SHOW);

				ShowWindow( hWndPrevious, SW_RESTORE );

				BringWindowToTop( hWndPrevious );

				SetForegroundWindow( hWndPrevious );
					return FALSE; 
			} 
			// 繼續尋找下一個窗口 
			hWndPrevious = ::GetWindow(hWndPrevious,GW_HWNDNEXT);
		} 
		// 前一實例已存在，但找不到其主窗 
		// 可能出錯了 
		// 退出本實例 

		return FALSE;

	}

	// Return success

	return TRUE;

}



CString CSingleInstance::GetClassName( void ) const

{

	return m_strClassName;

}