mfc经典案例

voidCLeftView::OnInitialUpdate(){CTreeView::OnInitialUpdate();CRuntimeClass*prc=RUNTIME_CLASS(CLeftView);BOOLb=prc->IsDerivedFrom(RUNTIME_CLASS(CDC));b=this->IsKindOf(RUNTIME_CLASS(CDC));staticinti=0;if(i)return;++i;ModifyStyle(0,TVS_LINESATROOT|TVS_HASBUTTONS|TVS_SHOWSELALWAYS|TVS_HASLINES