Thread: Assertion error when looking for window handle

hi,
I tried implementing a tab control in an SDI document using a CFormView class but I am getting an assertion error:
This is the code I am using:

Code:

// RemoteView.cpp : implementation of the CRemoteView class
//

#include "stdafx.h"
#include "Remote.h"

#include "RemoteDoc.h"
#include "RemoteView.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// CRemoteView

IMPLEMENT_DYNCREATE(CRemoteView, CFormView)

BEGIN_MESSAGE_MAP(CRemoteView, CFormView)
	ON_NOTIFY(TCN_SELCHANGE, IDC_TAB1, OnTabChange)
END_MESSAGE_MAP()

// CRemoteView construction/destruction

CRemoteView::CRemoteView()
	: CFormView(CRemoteView::IDD)
{
	// TODO: add construction code here

	CRect r;
	TCITEM tci;
	// get dimensions of client area
	GetClientRect(&r);
	// create tab control
	theTabControl.Create(WS_VISIBLE | WS_CHILD,r, this, IDC_TAB1);
	tci.mask = TCIF_TEXT;
	tci.iImage = -1;
	tci.pszText = "One";
	theTabControl.InsertItem(0, &tci);
	tci.pszText = "Two";
	theTabControl.InsertItem(1, &tci);
	tci.pszText = "Three";
	theTabControl.InsertItem(2, &tci);
}

CRemoteView::~CRemoteView()
{
}

void CRemoteView::DoDataExchange(CDataExchange* pDX)
{
	CFormView::DoDataExchange(pDX);
}

BOOL CRemoteView::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CFormView::PreCreateWindow(cs);
}

void CRemoteView::OnInitialUpdate()
{
	CFormView::OnInitialUpdate();
	GetParentFrame()->RecalcLayout();
	ResizeParentToFit(false);
	//initializeTabs();
}

// CRemoteView message handlers
afx_msg void CRemoteView::OnTabChange(NMHDR *hdr,LRESULT *NotUsed)
{
  CClientDC DC(this);
  char str[255];
  wsprintf(str, "Changed to Tab %d  ",
           theTabControl.GetCurSel()+1); 
  DC.SetBkColor(RGB(200, 200, 200));
  DC.TextOut(40, 100, str, strlen(str));
}

The assertion is occuring in the constructor when GetClientRect(&r) is run.
The assertion error is occuring here:

Code:

_AFXWIN_INLINE void CWnd::GetClientRect(LPRECT lpRect) const
	{ ASSERT(::IsWindow(m_hWnd)); ::GetClientRect(m_hWnd, lpRect); }

It seems it can't find m_hWnd. I was wondering if anybody knew a way around that or could explain why it is so. Thanks
Amish

Oops, I dont think you can over-ride OnInitDialog() for a CFormView. I think the correct function to over-ride is OnInitialUpdate().

that works. Thanks
Amish