高校问答董小姐唱的什么意思:在vc中，我要用cdc给CStatic控件加载位图，在SelectObject（）后，为什么还要BitBlt（）呢？
来源：百度文库 编辑：高校问答 时间：2024/05/03 03:44:08
代码如下：
CRect rect;
GetDlgItem(STC_BMP)->GetClientRect(&rect);
HDC hDC = ::GetDC(::GetDlgItem(m_hWnd, STC_BMP));
HDC hMemDC = CreateCompatibleDC(hDC);
HBITMAP hBmp = (HBITMAP)LoadImage(AfxGetInstanceHandle(), g_szBmpName, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);
HBITMAP hOldBmp = (HBITMAP)SelectObject(hMemDC, hBmp);
BitBlt(hDC, 0, 0, rect.Width(), rect.Height(), hMemDC, 0, 0, SRCCOPY);
SelectObject(hMemDC, hOldBmp);
DeleteObject(hBmp);
DeleteDC(hMemDC);
::ReleaseDC(::GetDlgItem(m_hWnd, STC_BMP), hDC);
CRect rect;
GetDlgItem(STC_BMP)->GetClientRect(&rect);
HDC hDC = ::GetDC(::GetDlgItem(m_hWnd, STC_BMP));
HDC hMemDC = CreateCompatibleDC(hDC);
HBITMAP hBmp = (HBITMAP)LoadImage(AfxGetInstanceHandle(), g_szBmpName, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);
HBITMAP hOldBmp = (HBITMAP)SelectObject(hMemDC, hBmp);
BitBlt(hDC, 0, 0, rect.Width(), rect.Height(), hMemDC, 0, 0, SRCCOPY);
SelectObject(hMemDC, hOldBmp);
DeleteObject(hBmp);
DeleteDC(hMemDC);
::ReleaseDC(::GetDlgItem(m_hWnd, STC_BMP), hDC);
select只是选入DC，要把它显示出来，还是要调用Bitblt，将memDC里面的东西贴出来的。
深绿青蓝说的对，select就相当于我选了支笔，选好笔还要画吧，BitBlt就是用笔来画了。
以上两位说的很对