Process DTWAIN Messages and Notifications

Your application can optionally capture DTWAIN messages that are sent to your application when images are being acquired.   These messages not only inform you of the progress of the acquisition that is being done, it can allow you to keep or discard images, inspect or display images, adjust the image that was acquired by the device, etc. while the acquisition is occurring.  

Since TWAIN is a message driven protocol, you must be using a programming language that has a "callback" or delegate feature to take advantage of the messages and notifications.  The callback function is called by DTWAIN whenever an event or notification occurs.  Languages such as C, C++, C#, VB. Net, and others have the ability to set up callback functions that can then be invoked by external modules.

For more information see Processing DTWAIN Notifications.