Changing color of icons dynamically

From:

subashjayan@gmail.com

Newsgroups:

microsoft.public.vc.mfc

Date:

3 May 2006 04:38:38 -0700

Message-ID:

<1146656318.821103.144460@j33g2000cwa.googlegroups.com>

Hi,

I need to change the color of icons dynamically, when i try to change
the color by following the steps, the background color is getting
mismatched.

HICON CGenericMFCDlg::CreateGrayscaleIcon(HICON hIcon)
{
    HICON hGrayIcon = NULL;
    HDC hMainDC = NULL, hMemDC1 = NULL, hMemDC2 = NULL,hMaskDC
= NULL;
    BITMAP bmp;
    HBITMAP hOldBmp1 = NULL, hOldBmp2 = NULL,hOldBmp3 = NULL;
    ICONINFO csII, csGrayII;
    BOOL bRetValue = FALSE;

    bRetValue = ::GetIconInfo(hIcon, &csII);
    if (bRetValue == FALSE) return NULL;

    hMainDC = ::GetDC(NULL);
    hMemDC1 = ::CreateCompatibleDC(hMainDC);
    hMemDC2 = ::CreateCompatibleDC(hMainDC);
    hMaskDC = ::CreateCompatibleDC(hMainDC);
    if (hMainDC == NULL || hMemDC1 == NULL || hMemDC2 == NULL) return
NULL;

    if (::GetObject(csII.hbmColor, sizeof(BITMAP), &bmp))
    {
        DWORD dwWidth = csII.xHotspot*2;
        DWORD dwHeight = csII.yHotspot*2;

        csGrayII.hbmColor = ::CreateBitmap(dwWidth, dwHeight,
bmp.bmPlanes,
                                           bmp.bmBitsPixel, NULL);
        if (csGrayII.hbmColor)
        {
            hOldBmp1 = (HBITMAP)::SelectObject(hMemDC1, csII.hbmColor);
            hOldBmp2 = (HBITMAP)::SelectObject(hMemDC2,
csGrayII.hbmColor);
            hOldBmp3 = (HBITMAP)::SelectObject(hMaskDC, csII.hbmMask);

            //::BitBlt(hMemDC2, 0, 0, dwWidth, dwHeight, hMemDC1, 0, 0,

            // SRCCOPY);

            DWORD dwLoopY = 0, dwLoopX = 0;
            COLORREF crPixel = 0,crMaskPixel;
            BYTE byNewPixel = 0;

            for (dwLoopY = 0; dwLoopY < dwHeight; dwLoopY++)
            {
                for (dwLoopX = 0; dwLoopX < dwWidth; dwLoopX++)
                {
                    crPixel = ::GetPixel(hMemDC1, dwLoopX, dwLoopY);

                    crMaskPixel = ::GetPixel(hMaskDC, dwLoopX, dwLoopY);

                    byNewPixel = (BYTE)((GetRValue(crPixel)) +
                                        (GetGValue(crPixel)) +
                                        (GetBValue(crPixel)));

                    int R = GetRValue(crPixel);
                    int B = GetBValue(crPixel);
                    int G = GetGValue(crPixel);

                    int R2 = GetRValue(crMaskPixel);
                    int B2 = GetBValue(crMaskPixel);
                    int G2 = GetGValue(crMaskPixel);

                    // Here are we can add one checking and change the color we
need.
                    if (crPixel)
                        ::SetPixel(hMemDC2, dwLoopX, dwLoopY,
                                            RGB(R,G,B));
                    else
                        TRACE("test");
                } // for
            } // for

            ::SelectObject(hMemDC1, hOldBmp1);
            ::SelectObject(hMemDC2, hOldBmp2);

            csGrayII.hbmMask = csII.hbmMask;

            csGrayII.fIcon = TRUE;
            hGrayIcon = ::CreateIconIndirect(&csGrayII);
        } // if

        ::DeleteObject(csGrayII.hbmColor);
        //::DeleteObject(csGrayII.hbmMask);
    } // if

    ::DeleteObject(csII.hbmColor);
    ::DeleteObject(csII.hbmMask);
    ::DeleteDC(hMemDC1);
    ::DeleteDC(hMemDC2);
    ::ReleaseDC(NULL, hMainDC);

    return hGrayIcon;
} // End of CreateGrayscaleIco

I got this sample from CodeProject.

Please help me

Subash