Opening the DSM in a console application:"reading viola

[twainuser123]

Hi,

First, sorry I am a relatively new programmer, so I do not have any experience with Windows API.
I am using Visual C++ on Windows Vista.

I am trying to make a non-GUI application using console windows (black box screens), but I am stuck on the part of loading the DSM, which asks me for a hWnd.
I am wondering why the code below does not work (it compiles but I keep getting “reading access violation” messages at run-time on the address of ‘parentWindow ‘):

HWND parentWindow = GetConsoleWindow();



//Open the Data Source Manager

TW_UINT16 returnCode = _DSM_Entry(&appIdentity, NULL, DG_CONTROL, DAT_PARENT, MSG_OPENDSM, (TW_MEMREF)parentWindow);

if ((appIdentity.SupportedGroups & DF_DSM2) == DF_DSM2)

{	//Check for DSM2 support

}

Thank you in advance!

[jimwatters]

The last parameter for MSG_OPENDSM on Windows is a pointer to a windows handle.

TW_UINT16 returnCode = _DSM_Entry(&appIdentity, NULL, DG_CONTROL, DAT_PARENT, MSG_OPENDSM, (TW_MEMREF)&parentWindow);

Jim Watters

[twainuser123]

I knew it was something simple.
Thanks for your help! 😛

One more question. How come this code to load a data source does not work? ‘returnCode’ is set to 1 when I run this code:
(appIdentity was defined before this code is called)

//The current TWAIN source we are looking at

TW_IDENTITY curSource;

//We call DSM_Entry to give us the next scanner Source

returnCode = _DSM_Entry(&appIdentity, 0, DG_CONTROL, DAT_IDENTITY, MSG_GETFIRST, (TW_MEMREF)&curSource);

[jimwatters]

Two things you can do to track down what is happening:

Enabling the DSM log file can help.
http://www.twainforum.org/viewtopic.php?t=4138

Get the Condition Code after a failure.

  TW_STATUS status;

memset(&status, 0, sizeof(TW_STATUS));

TW_UINT16 twrc = _DSM_Entry( &m_MyInfo, _pdestID, DG_CONTROL, DAT_STATUS, MSG_GET, (TW_MEMREF)&status);

Jim Watters

[sureshkallem]

hi,

I created console application by twain dll, by using this application I can able to read/scan the images but control not coming back to console application from twain GUI once scanning has been done.
Please help me on the same

[ilyes]

Hello,
I try to develop a Twain console application with visual studio (c++).
Can you help me please?

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