利用画面保存设备上下文

今天搞了下画图。。。。

没有实现自己想要的结果。。。

总有闪烁的问题。。。。明天来解决了。。。要熄灯了

BOOL CDBufferDlg::OnEraseBkgnd( CDC* pDC )
{
 CDC MemDc;
 CRect rt;
 this->GetClientRect(&rt);
 MemDc.CreateCompatibleDC(pDC);
 MemDc.SelectObject(&m_Bitmap[0]);
// pDC->BitBlt(0,0,m_hBitmap[0].bmWidth,m_hBitmap[0].bmHeight,&MemDc,0,0,SRCCOPY);
 pDC->StretchBlt(0,0,rt.Width(),rt.Height(),&MemDc,0,0,m_hBitmap[0].bmWidth,m_hBitmap[0].bmHeight,SRCCOPY);
 return FALSE;
}

void CDBufferDlg::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
 // TODO: Add your message handler code here and/or call default
 CRect rt;
 GetClientRect(&rt);
 switch(nChar)
 {
 case 'W':
  {
   if (y>rt.top&&y<rt.bottom)
   {
    y = y-m_Speed;
   }
   m_Mode = UP;
   SetBitmap(UP);
  }
  break;
 case 'S':
  {
   if (y<rt.bottom-40&&y>=rt.top)
   {
    y = y+m_Speed;
   }
   m_Mode = DOWN;
   SetBitmap(DOWN);
  }
  break;
 case 'A':
  {
   if (x>rt.left&&x<=rt.right)
   {
    x = x-m_Speed;
   }
   m_Mode = LEFT;
   SetBitmap(LEFT);
  }
  break;
 case 'D':
  {
   if (x>=rt.left&&x<rt.right-40)
   {
    x = x+m_Speed;
   }
   m_Mode = RIGHT;
   SetBitmap(RIGHT);
  }
  break;
 default:
  break;
 }
// InvalidateRect(&rt,TRUE);
 CDialog::OnKeyDown(nChar, nRepCnt, nFlags);
}

void CDBufferDlg::SetBitmap(Mode mode)
{
 CRect rt;
 GetClientRect(&rt);
 CDC memDC;
 CDC *pDC = GetDC();
 memDC.CreateCompatibleDC(pDC);
 memDC.SelectObject(&m_Bitmap[mode]);
 int i = pDC->SaveDC();
 CRgn rgn;
 rgn.CreateRectRgn(0,0,m_hBitmap[mode].bmWidth,m_hBitmap[mode].bmHeight);
 pDC->SelectClipRgn(&rgn);
 pDC->BitBlt(x,y,m_hBitmap[mode].bmWidth,m_hBitmap[mode].bmHeight,&memDC,0,0,SRCCOPY);
 pDC->RestoreDC(i);
 pDC->BitBlt(x,y,m_hBitmap[mode].bmWidth,m_hBitmap[mode].bmHeight,&memDC,0,0,SRCCOPY);
 
}