First, please make sure you set MaxImagesInBuffer Property properly so that the control will store multiple images in buffer.

1. The SaveAllAsPDF method can be used to save all images in buffer as a multi-page PDF file. Click here to get more information about this method.

2. The HTTPUploadAllThroughPostAsPDF method can be used to upload all images in buffer to the HTTP server as a multi-page PDF file. Click here to get more information about this method.