Richedit how to turn off this feature that make sure the ole could be seen.? About ITextServices::TxDraw and ITextHost::SetClientRect.

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C++

MFC

WTL

hi,

My English is not good, if the problem can not be Bunderstood please reply to me.



I ran into a problem.

I insert a picture into my richedit,than Scroll bars are displayed.

I move the scroll bar until Image the lower half of the display,

than i call the function "ITextHost::SetClientRect",i found that The scroll bar will automatically scroll to make sure the picture all visible.

if i do not call the function "ITextServices::TxDraw",Scroll bar does not automatically scroll.



Is there a way to disable the scrollbar rollback??



the function "ITextHost::SetClientRect"

void CTxtWinHost::SetClientRect(RECT *prc, BOOL fUpdateExtent) 
{
	// If the extent matches the client rect then we assume the extent should follow
	// the client rect.
	LONG lTestExt = DYtoHimetricY(
		(rcClient.bottom - rcClient.top)  - 2 * HOST_BORDER, yPerInch);

	if (fUpdateExtent 
		&& (sizelExtent.cy == lTestExt))
	{
		sizelExtent.cy = DXtoHimetricX((prc->bottom - prc->top) - 2 * HOST_BORDER, 
			xPerInch);
		sizelExtent.cx = DYtoHimetricY((prc->right - prc->left) - 2 * HOST_BORDER,
			yPerInch);
	}

	rcClient = *prc; 
}

the function "ITextServices::TxDraw"

void CxRichEdit::OnPaint(GDIPlus& gp, const CxRect& rcPaint)
{
	RECT rcTemp = { 0 };
	if( !::IntersectRect(&rcTemp, &rcPaint, &m_rcItem) ) return;

	if( m_pTwhost&&m_pTwhost->pserv ) 
	{
		RECT rc={0,0,0,0};
		m_pTwhost->GetControlRect(&rc);
		RECT rcNeedUpdate = rc;
		if(pPaintCenter)
			rcNeedUpdate = pPaintCenter->GetRectUpdate(rc);
		if(::IsRectEmpty(&rcNeedUpdate))return;


		RECT *prc = NULL;
		LONG lViewId = TXTVIEW_ACTIVE;

		//if (!m_pTwhost->GetActiveState())
		{
			prc = &rc;
			//lViewId = TXTVIEW_INACTIVE;
		}

		// Remember wparam is actually the hdc and lparam is the update
		// rect because this message has been preprocessed by the window.
		m_pTwhost->GetTextServices()->TxDraw(
			DVASPECT_CONTENT,  // Draw Aspect
			0,		// Lindex
			NULL,		// Info for drawing optimazation
			NULL,		// target device information
			gp.m_hDC,	// Draw device HDC
			NULL, 		// Target device HDC
			(RECTL *) prc,	// Bounding client rectangle
			NULL, 		// Clipping rectangle for metafiles
			(RECT*)&rcNeedUpdate,	// Update rectangle
			NULL, 	   	// Call back function
			NULL,		// Call back parameter
			lViewId);	// What view of the object			

	}
}