Description: Abstract
In Windows imaging applications, the most used API for scanning is TWAIN www.twain.org. Unfortunately, the new .NET Framework has no built-in support for TWAIN. So we have to work with the interop methods of .NET to access this API. This article doesn t explain this interop techniques, and good knowledge of the TWAIN 1.9 specifications is assumed! The sample code included doesn t present a finished library, only some essential steps for a minimal TWAIN adaption to .NET applications.
Details
First step was to port the most important parts of TWAIN.H, these are found in TwainDefs.cs. The real logic for calling TWAIN is coded in the class Twain, in file TwainLib.cs.. As the TWAIN API is exposed by the Windows DLL, twain_32.dll, we have to use the .NET DllImport mechanism for interop with legacy code. This DLL has the central DSM_Entry(), ordinal#1 function exported as the entry point to TWAIN. This call has numerous parameters, and the last one is of variable type! It was f
File list (Check if you may need any files):
Twain_App_sample01\ChangeLog.txt
..................\Doxyfile
..................\Installer
..................\.........\App Installer 32.vdproj
..................\.........\App Installer 64.vdproj
..................\.........\App Installer.sln
..................\.........\BannerTWAIN.bmp
..................\.........\twain.ico
..................\license.txt
..................\README.txt
..................\src
..................\...\DSMInterface.cpp
..................\...\DSMInterface.h
..................\...\main.cpp
..................\...\main.h
..................\...\src.pro
..................\...\Twain_App_sample01.cpp
..................\...\TwainApp.cpp
..................\...\TwainApp.h
..................\...\TwainApp_ui.cpp
..................\...\TwainApp_ui.h
..................\...\TwainAppCMD.cpp
..................\...\TwainAppCMD.h
..................\...\VerifySignature.cpp
..................\templates
..................\.........\cpp
..................\.........\h
..................\TODO.txt
..................\Twain_App_sample01.pro
..................\TWAIN1.9_compliancy_checklist.txt
..................\visual_studio
..................\.............\TWAIN_APP_VS2003.sln
..................\.............\TWAIN_APP_VS2003.vcproj
..................\.............\TWAIN_APP_VS2005.sln
..................\.............\TWAIN_APP_VS2005.vcproj
..................\visual_studio_mfc
..................\.................\mfc.cpp
..................\.................\mfc.h
..................\.................\mfc.rc
..................\.................\mfcDlgConfigure.cpp
..................\.................\mfcDlgConfigure.h
..................\.................\mfcDlgMain.cpp
..................\.................\mfcDlgMain.h
..................\.................\res
..................\.................\...\mfc.rc2
..................\.................\...\twain.ico
..................\.................\resource.h
..................\.................\stdafx.cpp
..................\.................\stdafx.h
..................\.................\TW_Array_Dlg.cpp
..................\.................\TW_Array_Dlg.h
..................\.................\TWAIN_APP_VS2003_mfc.sln
..................\.................\TWAIN_APP_VS2003_mfc.vcproj
..................\.................\TWAIN_APP_VS2005_mfc.sln
..................\.................\TWAIN_APP_VS2005_mfc.vcproj
..................\.................\TWAIN_APP_VS6_mfc.dsp
..................\.................\TWAIN_APP_VS6_mfc.dsw
common\Common.h
......\CommonTWAIN.cpp
......\CommonTWAIN.h
......\CTiffWriter.cpp
......\CTiffWriter.h
......\TwainString.cpp
......\TwainString.h
pub\bin
...\...\TWAIN_logo.png
...\external
...\........\bin
...\........\...\FreeImage.dll
...\........\...\FreeImagedx64.dll
...\........\...\FreeImagex64.dll
...\........\include
...\........\.......\FreeImage.h
...\........\.......\twain.h
...\........\lib
...\........\...\FreeImage.lib
...\........\...\FreeImagedx64.lib
...\........\...\FreeImagex64.lib
...\include
...\lib
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