ImageGear for C and C++ on Windows v21.0 - Updated
API Reference Guide / Core Component API Reference / Core Component Functions Reference / GUI Functions / GUI Thumbnail Functions / IG_GUI_thumbnail_CB_register
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    IG_GUI_thumbnail_CB_register
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    Call this function to register a callback function that is to be called whenever a thumbnail is selected in thumbnail window hWndThumbnail.

    Declaration:

     
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    AT_ERRCOUNT ACCUAPI IG_GUI_thumbnail_CB_register (
            HWND hWndThumbnail,
            LPFNIG_GUITHUMBSELECT lpfnThumbSelect, 
            LPVOID lpPrivate 
    ); 
    

    Arguments:

    Name Type Description
    hWndThumbnail HWND Windows handle to the Thumbnail window.
    lpfnThumbSelect LPFNIG_GUITHUMBSELECT A pointer to the callback function that you are registering, to be called whenever a thumbnail is selected.
    lpPrivateData LPVOID A far pointer to any private data to which you want to pass to the callback.

    Return Value:

    Returns the number of ImageGear errors that occurred during this function call.

    Supported Raster Image Formats:

    This function does not process image pixels.

    The callback used with this function correctly reports color space and bit depth for these pixel formats only:

    Indexed RGB – 1, 4, 8 bpp;
    Grayscale – 9…16 bpp;
    RGB – 24 bpp;
    CMYK – 32 bpp.

    Sample:

    Thumbnail, Display, FlashPix

    Example:

    For an example showing the use of this and other IG_GUI_Thumbnail functions and callbacks, see the Thumbnail sample application.

    Remarks:

    See also the description for callback type LPFNIG_GUITHUMBSELECT.