C / C++ / MFC

class CTestDlg : public CDialog
{
public:
	// ......

public:
	void TextOutPut(CString str,
					HFONT	hNew,
					HFONT	&hOld,
					SIZE	&szt)
	{
		CClientDC	dc(this);
		
		// Set the back and text color 
		GetWindowRect(&rt);
		dc.SetBkColor(RGB(255,255,255));
		dc.SetTextColor(RGB(0,0,0));
		dc.SetMapMode(MM_TEXT);

		// Use CClientDC::TextOut
		hOld = (HFONT)::SelectObject(dc,hNew);
		dc.TextOut(0,0,str);

		// I can use this function to get the szt's value like 32*33
		GetTextExtentPoint32(dc,str,str.GetLength(),&szt);

		COLORREF cr;
		POINT	 pt;

		// Now start to find the pixcel's RGB value.
		for (int i=0; i<szt.cy; i++)
		{
			for (int j=0; j<szt.cx; j++)
			{
				pt.x = j;
				pt.y = i;
				cr = dc.GetPixel(pt);

				if( -1 == cr )
				{
					TRACE("Call GetPixel Failed !\r\n");
				}
				else if( RGB(255,255,255) == cr )
				{
					CString str;
					str.Format("cur pix position: x=%d y=%d is white.",j,i);
					TRACE(str);
					// Do something.
				}
				else if( RGB(0,0,0) == cr )
				{
					CString str;
					str.Format("cur pix position: x=%d y=%d is black.",j,i);
					TRACE(str);
					// Do something.
				}
			}
		}
	}
};

C:\Program Files\Microsoft SDKs\Windows\v6.0A\include\oleacc.h(53) : error C2872: 'IAccessible' : ambiguous symbol
        could be 'C:\Program Files\Microsoft Visual Studio 9.0\VC\atlmfc\include\afxwin.h(1336) : IAccessible'
        or       'e:\Program\debug\mso.tlh(2072) : Office::IAccessible'