mfc画波形函数

void CMyPicoTestDlg::DrawWave(CDC *pDC,CRect &rectPicture)
{
    float fDeltaX;  
    float fDeltaY;
    int nX;
    int nY;
    CPen newPen;
    CPen *pOldPen;
    CBrush newBrush;
    CBrush *pOldBrush;

    fDeltaX=(float)rectPicture.Width()/(POINT_COUNT-1);
    fDeltaY=(float)rectPicture.Height()/80;

    newBrush.CreateSolidBrush(RGB(0,0,0));

    pOldBrush=pDC->SelectObject(&newBrush);
    pDC->Rectangle(rectPicture);
    pDC->SelectObject(pOldBrush);
    newBrush.DeleteObject();

    newPen.CreatePen(PS_SOLID,1,RGB(0,255,0));
    pOldPen=pDC->SelectObject(&newPen);

    pDC->MoveTo(rectPicture.left,rectPicture.bottom);
    
    for (int i=0;i<POINT_COUNT;i++)
    {
        nX=rectPicture.left+(int)(i*fDeltaX);
        nY=rectPicture.bottom-(int)(m_nzValue[i]*fDeltaY);
        pDC->MoveTo(nX,rectPicture.bottom);
        pDC->LineTo(nX,nY);
    
    }
    pDC->SelectObject(pOldPen);
    newPen.DeleteObject();
}