// Get the active MDI child window.
CMDIChildWnd *pChild =
(CMDIChildWnd *) pFrame->GetActiveFrame();
// or CMDIChildWnd *pChild = pFrame->MDIGetActive();
// Get the active view attached to the active MDI child
// window.CDisplayModeView是你定义的
CDisplayModeView *pView=(CDisplayModeView *) pChild->GetActiveView();
if(pView)
{
//刷新
pView->Invalidate(TRUE);
}