Problem with owner drawn listbox and double buffering

[aangerma]

Hello, I created owner drawn listbox and I used double buffering for preventing flickering because I have a lot of data , the problem is that its don't present all the items and , whan I scroll it down and up its erases part of the items, the code is:

void HistDlg::OnDrawItem(int nIDCtl, LPDRAWITEMSTRUCT lpDrawItemStruct)
{
if(IDC_LIST1 ==nIDCtl)
{
int width=lpDrawItemStruct->rcItem.right-lpDrawItemStruct->rcItem.left;
int height=lpDrawItemStruct->rcItem.bottom-lpDrawItemStruct->rcItem.top;
HDC memDC1 = CreateCompatibleDC(lpDrawItemStruct->hDC);
HBITMAP hMemBmp = CreateCompatibleBitmap(lpDrawItemStruct->hDC,width , height);
HBITMAP hOldBmp = (HBITMAP)SelectObject(memDC1, hMemBmp);
CDC *memDC=CDC::FromHandle(memDC1);
memDC->FillSolidRect(0,0, width, height,RGB(255,255,255));

	int	 ODI\_length =  
	1 + SendDlgItemMessage(IDC\_LIST1,
							   LB\_GETTEXTLEN,
							   lpDrawItemStruct->itemID,
							   0);

	if (ODI\_length)
	{
		wchar\_t \*ODI\_wstr = NULL;
		ODI\_wstr = new wchar\_t\[ODI\_length\];
		if (ODI\_wstr)
		{
			COLORREF ODI\_old\_text\_color;
			//get the string
			SendDlgItemMessage(IDC\_LIST1,
							   LB\_GETTEXT,
							   lpDrawItemStruct->itemID,
							   (LPARAM)ODI\_wstr);
				
				
			memDC->DrawText(ODI\_wstr,
						  ODI\_length - 1,
						  &lpDrawItemStruct->rcItem,
						  DT\_RIGHT);
			
		}

	}

	BitBlt(lpDrawItemStruct->hDC, 0, 0, width,height, memDC1, 0, 0, SRCCOPY);
	SelectObject(memDC1, hOldBmp);
	DeleteObject(hMemBmp);
	DeleteDC(memDC1);
}

}

What doe's I'm doing wrong? thanks

[CPallini]

aangerma wrote:

BitBlt(lpDrawItemStruct->hDC, 0, 0, width,height, memDC1, 0, 0, SRCCOPY);

Shouldn't this be:

LONG left = lpDrawItemStruct->rcItem.left;
LONG top = lpDrawItemStruct->rcItem.top;
BitBlt(lpDrawItemStruct->hDC, left, top, width,height, memDC1, 0, 0, SRCCOPY);

?

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