TwainSelectFeeder <-> TwainSetAutoFeed

Discussions about TWAIN & WIA scanning in GdPicture.NET using GdPictureImaging.
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TwainSelectFeeder <-> TwainSetAutoFeed

Post by benjamin » Thu Oct 28, 2010 11:31 am


What is the difference in the functions TwainSelectFeeder(true) and TwainSetAutoFeed(true)?
In your samples you always use the second one, does it have any advantages or are other properties configured automatically that I have to conigure manually if I use the first one?


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Re: TwainSelectFeeder <-> TwainSetAutoFeed

Post by Loïc » Thu Oct 28, 2010 4:15 pm


From the reference guide:
TwainSelectFeeder - Asks to the opened source to select or deselect the document feeder.

TwainSetAutoFeed - Try to enable or disable the Source’s automatic document feeding process. If you enable auto feed scanning, this function selects the feeder. So to start scanning pages from an ADF, just do: TwainSetAutoFeed(TRUE).

And from the TWAIN reference (TwainSetAutoFeed):
When set to TRUE, the behavior of the Source is to eject one page and feed the next page
after all frames on the first page are acquired. This automatic feeding process will
continue whenever there is image data ready for acquisition (and the Source is in an
enabled state)

In other words, the function TwainSelectFeeder sets the document feeder as source and the TwainSetAutoFeed sets the document feeder as source & enables the autofeed process decried above.

Kind regards,


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