原代码:
CMainFrame_* pFrame=(CMainFrame )(AfxGetApp()->m_pMainWnd);
CMFCImageView pView=(CMFCImageView*)pFrame->MDIGetActive()->GetActiveView();
CMFCImageDoc* pDoc=pView->GetDocument();
为什么不能直接写成:
CMainFrame* pFrame=(CMainFrame )(AfxGetApp()->m_pMainWnd);
CMFCImageDoc pDoc=(CMFCImageDoc*)pFrame->MDIGetActive()->GetActiveDocument();