I am using nested splitters CXTPSplitterWnd:

BOOL CMainFrame::OnCreateClient(LPCREATESTRUCT lpcs, CCreateContext* pContext){ if ( !m_wndSplitterHorz.CreateStatic(this, 2, 1) || !m_wndSplitterHorz.CreateView(1, 0, RUNTIME_CLASS(CXTPReportView), CSize(100, 100), pContext)) return FALSE; if ( !m_wndSplitterVert.CreateStatic(&m_wndSplitterHorz, 1, 2, WS_CHILD | WS_VISIBLE, m_wndSplitterHorz.IdFromRowCol(0, 0)) || !m_wndSplitterVert.CreateView(0, 0, RUNTIME_CLASS(CXTPReportView), CSize(100, 100), pContext) || !m_wndSplitterVert.CreateView(0, 1, RUNTIME_CLASS(CXTPReportView), CSize(100, 100), pContext)) return FALSE; m_wndSplitterHorz.SetRowInfo(0, 630, 0); m_wndSplitterVert.SetColumnInfo(0, 630, 0); CXTPControlTheme::SetTheme(m_hWnd, xtpControlThemeOffice2003); //return CMainFrameParrent::OnCreateClient(lpcs, pContext); return TRUE;}

Horizontal splitter can not be moved. And so with all the splitters who have sub splitters. If you set

m_wndSplitterHorz.EnableFullDrag(0)

everything works properly, but without full drag