BCGControlBar Pro for MFC
BOOL CBCGPToolBarImages::UpdateImage ( int  iImage,
HBITMAP  hbmp,
BOOL  bFitImage = FALSE,
BOOL  bPremultiplyAlpha = FALSE 

Updates a user-defined toolbar image from a bitmap.

Nonzero if the image was updated successfully; it is 0 if the image list is not user-defined or temporary.

Call this function to update a user-defined toolbar image at the specified position. The new image is copied from a bitmap specified by the hbmp parameter.

iImageSpecifies the zero-based index of image to update.
hbmpSpecifies a handle to bitmap to update the image from.
bFitImageTells whether an image should be fitted inside the image list item bounds.
bPremultiplyAlphaTells whether pre-multiplication operation should be performed for the added image.