ImageGear for C and C++ on Windows v19.6 - Updated
IG_GUI_thumbnail_CB_register
API Reference Guide > Core Component API Reference > Core Component Functions Reference > GUI Functions > GUI Thumbnail Functions > IG_GUI_thumbnail_CB_register

Call this function to register a callback function that is to be called whenever a thumbnail is selected in thumbnail window hWndThumbnail.

Declaration:

 
Copy Code
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.