Saving a windows size position and state in MFC

class CDialogExPos : public CDialogEx
{
	DECLARE_DYNAMIC(CDialogExPos)

public:
	CDialogExPos(UINT nResourceId,CWnd* pParent = NULL);   // Constructor con recurso de plantilla
	virtual ~CDialogExPos();

protected:
	// get the dialog resource id as string
	CString GetDlgResourceIdAsString();
	// get the module name from wich the dialog resource is being created (execution time)
	BOOL GetModuleBaseName(CString &moduleName);
	// recover dlg placement from registry
	void GetPreviousPositionSettings();
	// save dlg placement from registry
	void SaveCurrentPositionSettings();
	virtual void DoDataExchange(CDataExchange* pDX);    // Compatibilidad con DDX/DDV

	DECLARE_MESSAGE_MAP()
private:
	UINT m_dlgResourceId;
public:
	virtual BOOL DestroyWindow();
	
	afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
};

#include "stdafx.h"
#include "DialogExPos.h"
#include "afxdialogex.h"

TCHAR szDlgPlacement[] = _T("_WndPlacements");
// Cuadro de diálogo de CDialogExPos

IMPLEMENT_DYNAMIC(CDialogExPos, CDialogEx)


CDialogExPos::CDialogExPos(UINT nResourceId, CWnd* pParent) : CDialogEx(nResourceId, pParent)
{
	// guarda el id de recurso del dialogo necesario para almacenar las coordenadas de forma inequivoca para cada dialogo
	m_dlgResourceId = nResourceId;
}
CDialogExPos::~CDialogExPos()
{
}

void CDialogExPos::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}


BEGIN_MESSAGE_MAP(CDialogExPos, CDialogEx)
	ON_WM_CREATE()
	ON_WM_SHOWWINDOW()
END_MESSAGE_MAP()


// Controladores de mensajes de CDialogExPos
// Retores the previous window size from the registry
void CDialogExPos::GetPreviousPositionSettings()
{
	CString strModule;
	CString strIdDialog = GetDlgResourceIdAsString();

	WINDOWPLACEMENT *lwp;
	UINT nl;
	if (GetModuleBaseName(strModule) && !strIdDialog.IsEmpty())
	{
		// la función asigna el buffer de memoria requerido y nos devuelve el tamaño (que no precisamos)
		if (AfxGetApp()->GetProfileBinary(strModule + szDlgPlacement, strIdDialog, (LPBYTE*)&lwp, &nl))
		{
			SetWindowPlacement(lwp);
			// libera el buffer de memoria alojado
			delete[] lwp;
			return;
		}
	}
	CenterWindow();
}
BOOL CDialogExPos::GetModuleBaseName(CString &moduleName)
{
	TCHAR szPath[MAX_PATH*2];
	// create unique section name for dialog from current instance and dialog resource ID
	// recover full path of current resource handle (will match the dll being executed)
	if (GetModuleFileName(AfxGetResourceHandle(), szPath, _countof(szPath)) > 0)
	{
		// strip the path part
		PathStripPath(szPath);
		// and the extension, leaving us with only the dll filename
		PathRemoveExtension(szPath);
		// save as our module name
		moduleName = szPath;
		return TRUE;
	}
	return FALSE;
}
CString CDialogExPos::GetDlgResourceIdAsString()
{
	CString strSectionDialog;
	strSectionDialog.Format(_T("DLG_%08d"), m_dlgResourceId);
	return strSectionDialog;
}
// Saves the current window position registry
void CDialogExPos::SaveCurrentPositionSettings()
{
	if (!IsWindow(m_hWnd))
		return;
	CString strIdDialog = GetDlgResourceIdAsString();
	CString strModule;
	WINDOWPLACEMENT wp;
	if (GetWindowPlacement(&wp))
	{
		// overwrite to show state , so when the placement is recovered
		// it stays on the same recovered position otherwise the dialog is restored 
		// at its design position or centered on the parewt window
		wp.showCmd = SW_SHOW;
		if (GetModuleBaseName(strModule) && !strIdDialog.IsEmpty())
		{
			AfxGetApp()->WriteProfileBinary(strModule + szDlgPlacement, strIdDialog, (LPBYTE)&wp, sizeof(wp));
		}
	}
}

BOOL CDialogExPos::DestroyWindow()
{
	// TODO: Agregue aquí su código especializado o llame a la clase base
	SaveCurrentPositionSettings();
	return CDialogEx::DestroyWindow();
}


int CDialogExPos::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
	if (CDialogEx::OnCreate(lpCreateStruct) == -1)
		return -1;

	GetPreviousPositionSettings();

	return 0;
}

LRESULT MyClass::OnShowWindow(WPARAM wParam, LPARAM lParam)
{
	BOOL bShow = BOOL(wParam);
	UINT nStatus = (UINT)lParam;
	CResizableDialog::OnShowWindow(bShow, nStatus);

	WINDOWPLACEMENT *lwp;
	UINT nl;
	if(AfxGetApp()->GetProfileBinary(_T("MyKey"), _T("WP"), (LPBYTE*)&lwp, &nl))
	{
		if (lwp->flags == WPF_RESTORETOMAXIMIZED)
		{
			CResizableDialog::ShowWindow(SW_MAXIMIZE);
		}
		else
		{
			SetWindowPos(NULL,
				     lwp->rcNormalPosition.left,
				     lwp->rcNormalPosition.top,
				     lwp->rcNormalPosition.right - lwp->rcNormalPosition.left,
				     lwp->rcNormalPosition.bottom - lwp->rcNormalPosition.top,
				     NULL);
		}
		delete [] lwp;
	}

	return FALSE;
}