pDC,双缓冲 加载bitmap一点实践

1.在view里显示文字,很简单:

 (1)pDC->DrawText("DrawText",strlen("DrawText"),CRect(30,30,100,100),DT_CENTER);
 (2)pDC->TextOut(0,0,_T("测试"));

2.显示位图

CDC mem;

CBitmap ditu;
 BITMAP bm;

 mem.CreateCompatibleDC(NULL);

 ditu.LoadBitmap(IDB_MAP);//注意不要写成 ditu = LoadBitmap(IDB_MAP);
 ditu.GetBitmap(&bm);

 SelectObject(mem,ditu);  
(1)StretchBlt(pDC->GetSafeHdc(),0,0,bm.bmWidth,bm.bmHeight,mem,0,0,bm.bmWidth,bm.bmHeight,SRCCOPY);
(2)pDC->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&mem,0,0,SRCCOPY);

3.双缓冲防止闪烁

 CDC mem;
 CBitmap bitmap;
 CPen pen(PS_SOLID,3,RGB(0,0,255));
 CBrush brush(RGB(255,0,0));
 

 mem.CreateCompatibleDC(NULL);
 bitmap.CreateCompatibleBitmap(pDC,scaleRect.Width(),scaleRect.Height());

 mem.SelectObject(&pen);
 mem.SelectObject(&brush);
 mem.SelectObject(&bitmap);

 //mem.SetBkMode(TRANSPARENT);
 mem.FillSolidRect(0,0,scaleRect.Width(),scaleRect.Height(),RGB(111,111,111));

mem.Rectangle(&Rt);

pDC->BitBlt(0,0,Rt.Width(),Rt.Height(),&mem,0,0,SRCCOPY);