多文档程序 设置了子窗口style为WS_HSCROLL 怎么用

BOOL

CSmartEditorView::PreCreateWindow(CREATESTRUCT& cs) 

{

	// TODO: Add your specialized code here and/or call the base class

	

	CWnd *pParentWnd = CWnd::FromHandlePermanent( cs.hwndParent );

	if( NULL == pParentWnd ||

		!pParentWnd->IsKindOf( RUNTIME_CLASS( CSplitterWnd ) ) )

	{

		//	View must always create its own scrollbars,

		//	if only it's not used within splitter

		cs.style |= ( WS_HSCROLL | WS_VSCROLL );

	}

	cs.lpszClass = AfxRegisterWndClass( CS_DBLCLKS );

	return CView::PreCreateWindow(cs);

}



void CSmartEditorView::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar) 

{

	// TODO: Add your message handler code here and/or call default

	SCROLLINFO si;

	int page_lines, line_count, new_topline;

	

	CView::OnVScroll(nSBCode, nPos, pScrollBar);



	//	Note we cannot use nPos because of its 16-bit nature

	memset( &si, 0, sizeof( SCROLLINFO ) );



	si.cbSize = sizeof( SCROLLINFO );

	si.fMask = SIF_ALL;

	VERIFY( GetScrollInfo( SB_VERT, &si ) );



	page_lines = GetScreenLines();

	line_count = GetLineCount();



	switch( nSBCode )

	{

	case SB_TOP:

		new_topline = 0;

		break;

	case SB_BOTTOM:

		new_topline = line_count - page_lines + 1;

		break;

	case SB_LINEUP:

		new_topline = m_top_line - 1;

		break;

	case SB_LINEDOWN:

		new_topline = m_top_line + 1;

		break;

	case SB_PAGEUP:

		new_topline = m_top_line - si.nPage + 1;

		break;

	case SB_PAGEDOWN:

		new_topline = m_top_line + si.nPage - 1;

		break;

	case SB_THUMBPOSITION:

	case SB_THUMBTRACK:

		new_topline = si.nTrackPos;

		break;

	default:

		return;

	}



	if( new_topline < 0 )

	{

		new_topline = 0;

	}



	if( new_topline >= line_count )

	{

		new_topline = line_count - 1;

	}



	BOOL bUpdateSiblings = FALSE;

	if( m_top_line != new_topline )

	{

		int scroll_line_count = m_top_line - new_topline;

		m_top_line = new_topline;

		ScrollWindow( 0, scroll_line_count * GetLineHeight() );

		UpdateWindow();

	}



	RecalcVScrollBar( TRUE );

}



void

CSmartEditorView::RecalcVScrollBar( BOOL bPositionOnly )

{

	SCROLLINFO si;



	memset( &si, 0, sizeof( SCROLLINFO ) );

	si.cbSize = sizeof( SCROLLINFO );



	if( bPositionOnly )

	{

		//只更新区域，应该是用户纯滚动屏幕

		si.fMask = SIF_POS;

		si.nPos = m_top_line;

	}

	else

	{

		if( GetScreenLines() >= GetLineCount() && m_top_line > 0)

		{

			m_top_line = 0;

			Invalidate();

		}

		si.fMask = SIF_DISABLENOSCROLL | SIF_PAGE | SIF_POS | SIF_RANGE;

		si.nMin = 0;

		si.nMax = GetLineCount() - 1;

		si.nPage = GetScreenLines();

		si.nPos = m_top_line;

	}



	VERIFY( SetScrollInfo( SB_VERT, &si ) );

}

void CMyView::Create(CWnd *pParentWnd, const RECT &rect, UINT nID, DWORD dwStyle)

{

    CView::Create(NULL, "", dwStyle, rect, pParentWnd, nID);



    m_HScrollBar.Create( SBS_HORZ | SBS_TOPALIGN, CRect( rect.left, rect.bottom, rect.right - rect.left, 20), pParentWnd, 0 );

    m_HScrollBar.ShowScrollBar();

}