MFC中显示一张位图

1、用类CBitmap加载位图

2、创建内存DC， 将位图选进此内存DC

3、调用BitBlt将内存DC的内容拷贝到其它DC(通知是显示DC)

例子（来自MSDN)：

// This OnDraw() handler loads a bitmap from system resources,
// centers it in the view, and uses BitBlt() to paint the bitmap
// bits.

void CBlat2View::OnDraw(CDC* pDC)
{
   CBlat2Doc* pDoc = GetDocument();
   ASSERT_VALID(pDoc);

   // load IDB_BITMAP1 from our resources
   CBitmap bmp;
   if (bmp.LoadBitmap(IDB_BITMAP1))
   {
      // Get the size of the bitmap
      BITMAP bmpInfo;
      bmp.GetBitmap(&bmpInfo);

      // Create an in-memory DC compatible with the
      // display DC we're using to paint
      CDC dcMemory;
      dcMemory.CreateCompatibleDC(pDC);

      // Select the bitmap into the in-memory DC
      CBitmap* pOldBitmap = dcMemory.SelectObject(&bmp);

      // Find a centerpoint for the bitmap in the client area
      CRect rect;
      GetClientRect(&rect);
      int nX = rect.left + (rect.Width() - bmpInfo.bmWidth) / 2;
      int nY = rect.top + (rect.Height() - bmpInfo.bmHeight) / 2;

      // Copy the bits from the in-memory DC into the on-
      // screen DC to actually do the painting. Use the centerpoint
      // we computed for the target offset.
      pDC->BitBlt(nX, nY, bmpInfo.bmWidth, bmpInfo.bmHeight, &dcMemory, 
         0, 0, SRCCOPY);

      dcMemory.SelectObject(pOldBitmap);
   }
   else
      TRACE0("ERROR: Where's IDB_BITMAP1?
");
}