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I'm trying to set up a C# application which uses TWAIN example from code project

This works fine except that I need to cast Form to IMessageFilter and call IMessageFilter.PreFilterMessage() to catch TWAIN callbacks.
Also I need to start this filtering by calling

Application.AddMessageFilter();

Is there a way to do same thing in WPF Window? (To add message filter and catch TWAIN callbacks).

Another totally high level question: Does anybody know about alternative C# TWAIN libraries\wrappers?

Thank you.

Hakan Fıstık
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Valentin V
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3 Answers3

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I've just wrapped up the code from Thomas Scheidegger's article (CodeProject: .NET TWAIN image scanning) into github project

I've cleaned up the API a bit and added WPF support, so check it out. :)

It has a simple WPF application that shows how the message filtering works with WPF.

Hakan Fıstık
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Luke Quinane
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You could try it with the ComponentDispatcher.ThreadFilterMessage event.
As far as I understand, it serves the same purpose in WPF as Application.AddMessageFilter() in WinForms.

Hakan Fıstık
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csgero
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I thought TWAIN is considered obsolete. Maybe take a look at WIA, that does this job since WinXP. There is also a sample at codeproject. About the WPF related question, no idea, I only used it in windows forms apps.

driAn
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    driAn, TWAIN is *older* but not obsolete. It has vast devices support. Also, my scanner does not (oddly) support WIA. – Valentin V Jan 24 '09 at 15:47
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    Well, microsoft considers it being obsolete, they suggest using WIA instead. – driAn Jan 24 '09 at 15:53
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    Hmm... There's no causal relation between Microsoft opinions and consensus reality, in either direction. I work with TWAIN, and at least for document scanning, WIA is obsolete and has been since it was introduced. They introduced it during a brief phase when they were excited about clobbering Apple. Then the Burning Eye turned to other things, and it has languished ever since. I recommend it for digital cameras though. – Spike0xff Jul 03 '09 at 00:31