如何在对话框上显示一个位图？不用任何控件，就在背景？

Question

如何在对话框上显示一个位图？不用任何控件，就在背景？
这样显示了以后，用CClientDC能操作上面的像素吗？
请问如何搞定啊

Answer 1

CDC *pDC=GetDC();
Bitmap.LoadBitmap(IDB_1);
dcMemory.CreateCompatibleDC(pDC);
CBitmap* OldBitmap=dcMemory.SelectObject(&Bitmap);

pDC->BitBlt(0,0,495,495,&dcMemory,0,0,SRCCOPY);
 
Bitmap.DeleteObject();
dcMemory.SelectObject(OldBitmap);
dcMemory.DeleteDC();
ReleaseDC(pDC);

Answer 2

BOOL CMyDlg::OnEraseBkgnd(CDC* pDC)
{
    // Set brush to desired background color
    CBrush backBrush(RGB(192, 192, 192));//can be a image    // Save the old brush
    CBrush* pOldBrush = pDC->SelectObject(&backBrush);    // Get the current clipping boundary
    CRect rect;
    pDC->GetClipBox(&rect);    // Erase the area needed
    pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(),
         PATCOPY);    pDC->SelectObject(pOldBrush); // Select the old brush back
    return TRUE;  // message handled
}

Answer 3

BOOL CMyDlg::OnEraseBkgnd(CDC* pDC)
{
         CRect  rect;
GetWindowRect(&rect); CDC memDC;
         CBitmap           m_bmpMain.LoadBitmap(IDB_BITMAP1);
CBitmap &cBitmap=m_bmpMain;
CBitmap* pOldMemBmp = NULL;

memDC.CreateCompatibleDC(pDC);
pOldMemBmp = memDC.SelectObject(&cBitmap);
pDC->BitBlt(0, 0, rect.Width(), rect.Height(), &memDC, 0, 0, SRCCOPY);


if (pOldMemBmp) memDC.SelectObject( pOldMemBmp );
    
return TRUE;
}

Answer 4

设lpszName 是你要加载的位图路径，pDC是显示DC
则：
    const char* lpszName = "c:\\test.bmp";
    HBITMAP hBitmap = (HBITMAP)::LoadImage(NULL,
                                            lpszName,
                                            IMAGE_BITMAP,
                                             0,
                                             0,
                                              LR_LOADFROMFILE);
    CBitmap bmp;
    bmp.Attach(hBitmap);
    BITMAP bm;
    bmp.GetBitmap(&bm);
    CDC memDC;
    memDC.CreateCompatibleDC(pDC);
    CBitmap *pOldBmp = memDC.SelectObject(&bmp);
    pDC->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&memDC,0,0,SRCCOPY);    memDC.SelectObject(pOldBmp);
---------------------------------------
void CTestListDlg::OnPaint() 
{
    CPaintDC dc(this); // device context for painting
    
    // TODO: Add your message handler code here
    HBITMAP hBitmap;    hBitmap=(HBITMAP)LoadImage(
      ::AfxGetInstanceHandle(),"res\\background.bmp",
      IMAGE_BITMAP,0,0,
      LR_LOADFROMFILE|LR_CREATEDIBSECTION);
    ASSERT( hBitmap);
    HBITMAP hOldBitmap;
    
    CDC MemDC;
   CRect rect;
   CDC *pDC=this->GetDC();
   MemDC.CreateCompatibleDC(pDC);
   GetClientRect(rect);
   hOldBitmap=(HBITMAP)MemDC.SelectObject(hBitmap);
   pDC->BitBlt(0,0,rect.Width(),rect.Height(),&MemDC,0,0,SRCCOPY);
   MemDC.SelectObject(hOldBitmap);    // Do not call CDialog::OnPaint() for painting messages
}

Answer 5

BOOL CMyDlg::OnEraseBkgnd(CDC* pDC)
{
    // Set brush to desired background color
    CBrush backBrush(RGB(192, 192, 192));//can be a image    // Save the old brush
    CBrush* pOldBrush = pDC->SelectObject(&backBrush);    // Get the current clipping boundary
    CRect rect;
    pDC->GetClipBox(&rect);    // Erase the area needed
    pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(),
         PATCOPY);    pDC->SelectObject(pOldBrush); // Select the old brush back
    return TRUE;  // message handled
}

Answer 6

CDC * pDC = GetDC();
   HBITMAP bitmap1;
   /////读取位图文件(转炉.bmp)
   bitmap1=(HBITMAP)LoadImage(AfxGetInstanceHandle(),"转炉.bmp",IMAGE_BITMAP,0,0,LR_LOADFROMFILE|LR_CREATEDIBSECTION);
   ASSERT(bitmap1);
   HBITMAP oldbitmap;
   CDC memdc;CRect rect;
   memdc.CreateCompatibleDC(pDC);
   GetClientRect(rect);
   oldbitmap=(HBITMAP)memdc.SelectObject(bitmap1);
   ///显示它
   pDC->BitBlt(270,50,rect.Width()-20,rect.Height()-20,&memdc,0,0,SRCCOPY);
   memdc.SelectObject(oldbitmap);

Answer 7

有些对话框没有ERASEBKGND，怎么回事

Answer 8

CDC *pDC=this->GetDC();
    CBitmap m_MyBitmap;
    m_MyBitmap.LoadBitmap (IDB_BITMAP1);    BITMAP bmp;
    m_MyBitmap.GetBitmap (&bmp);    CRect rect;
    pDC->GetClipBox(&rect);     CPoint org(0,0); 
    pDC->DPtoLP(&org);     CDC dcMem;
    dcMem.CreateCompatibleDC (pDC);
    CBitmap *pOldBitmap =dcMem.SelectObject (&m_MyBitmap);
    dcMem.SetMapMode (pDC->GetMapMode());
    pDC->StretchBlt (rect.left,rect.top,rect.Width(),rect.Height(),&dcMem,org.x,org.y,bmp.bmWidth, bmp.bmHeight, SRCCOPY);
    pDC->SelectObject (pOldBitmap);