Vc窗口下加载位图，为毛只有窗口没得图片呢？？？

// ckWnd.cpp : implementation file
//

//#include "stdafx.h"
#include "ck.h"
#include "ckWnd.h"

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

/////////////////////////////////////////////////////////////////////////////
// ckWnd

IMPLEMENT_DYNCREATE(ckWnd, CFrameWnd)
int i ;
ckWnd::ckWnd()
{
    Create(NULL, "窗口");
    bitmap = new CBitmap;
    bitmap->m_hObject= LoadImage(NULL, "1.1.bmp", IMAGE_BITMAP, 600, 450, LR_LOADFROMFILE);
    mdc = new CDC;
    CClientDC dc(this);
    mdc->CreateCompatibleDC(&dc);
    mdc->SelectObject(bitmap);
    i = 0;
}

ckWnd::~ckWnd()
{
}


BEGIN_MESSAGE_MAP(ckWnd, CFrameWnd)
    //{{AFX_MSG_MAP(ckWnd)
    ON_WM_PAINT()
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// ckWnd message handlers

void ckWnd::OnPaint()
{
    CPaintDC dc(this); // device context for painting
   
    // TODO: Add your message handler code here
    if (i++<300)
    {
        dc.BitBlt(0+i,0,600,450,mdc,0,0,SRCCOPY);
    }
    else
        i = 0;
    // Do not call CFrameWnd::OnPaint() for painting messages
}