C / C++ / MFC

COLORREF GetPixel(
   int x,
   int y 
) 

COLORREF color;
color=GetPixel(10,10);
int red=GetRValue(color);
int blue=GetBValue(color);
int green=GetGValue(color);

void MyApp::InvalidateAllViews()
{

    // Get position of first document template
    POSITION pos = m_pDocManager->GetFirstDocTemplatePosition();
    while( pos )
    {
        // Get pointer to document template
        CDocTemplate* pTemplate = m_pDocManager->GetNextDocTemplate(pos);
        // Get position of first document using template
        POSITION pos2 = pTemplate->GetFirstDocPosition();
        while( pos2 )
        {
            // Get pointer to document
            CMyDoc* pDoc = (CMysDoc*)(pTemplate->GetNextDoc(pos2));
            if( pDoc )
            {
                // Get position of first view
                POSITION pos3 = pDoc->GetFirstViewPosition();
                while( pos3 )
                {
                    // Get pointer of next view
                    CMyView* pView = (CVMyView*)(pDoc->GetNextView(pos3));
                    pView->Invalidate();
                }
            }
        }
    }
}