Canon TWAIN interface issue (CANNOT close source)

[Mishutak]

Hi all

we’re experiencing problems with the Canon TWAIN interface for ALL Canon scanners.
The problem is as follows:
Our application CANNOT receive message MSG_CLOSEDSREQ (hex 102) untill you move cusor out of Source (TWAIN driver) User interface window or activate this window programmatically (call Windows API function SetActiveWindow). So the Application CANNOT close source.

Source (TWAIN driver) User interface is called by a tripple:
DG_CONTROL, DAT_USERINTERFACE, MSG_ENABLEDS
(with ShowUI and ModalUI fields set to True).

Absolutely ALL the other TWAIN intefaces are working correct. Could you please advise us on how we can fix this issue with Canon ?

[brcbuzz]

Hi, Did you find a solution to your post? I am having the same problem…

My problem… My form is being loaded as modal. When attempting to scan the form is calling a Twain function “DSMident” and if the power if off on the scanner then a message is being display from the scanner driver. Since my form is modal I cannot close the message and it gives the appearance the application is frozen. I tried implementing the twain capability of CAP_DEVICEONLINE and it always returns false.

Dim capDeviceOnline As New TwCapability(TwCap.CAP_DEVICEONLINE)

rc = DScap(appid, srcds, TwDG.Control, TwDAT.Capability, TwMSG.[Get], capDeviceOnline)
If rc <> TwRC.Success Then
CloseSrc()
Return False
End If

VB.net on Windows 7 64 bit. Application is set as x86 using Twain_32.dll. Scanner is Canon DR-6010C.

[Mishutak]

We discovered that in the earlier version of our application it worked fine. At the moment we’re trying to understand the reason for that

[Author]

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