Ccmdtarget() assertion failure

Question

0.00/5 (No votes)

See more:

in my application need some scanner support ,I thought it is a good idea to get into TWAIN and try it out.after that I had an exit error that is driving me nuts as an Debug Assertion Failed....
in cmdtarg.cpp line 40 CCmdTarget::~CCmdTarget because m_dwRef is greater than 1 (in this case it is 2)

What I have tried:

CCmdTarget::~CCmdTarget()
{
	if (m_xDispatch.m_vtbl != 0)
		((COleDispatchImpl*)&m_xDispatch)->Disconnect();
	ASSERT(m_dwRef <= 1);
	m_pModuleState = NULL;
}

//Error message

'ScannerApp.exe' (Win32): Unloaded 'C:\Windows\twain_32.dll'
Debug Assertion Failed!

Program: C:\Windows\SYSTEM32\mfc140d.dll
File: d:\a01\_work\11\s\src\vctools\VC7Libs\Ship\ATLMFC\Src\MFC\cmdtarg.cpp
Line: 40

Posted 8-Dec-22 8:57am

Zouaoui Billel

Updated 9-Dec-22 8:58am

Add a Solution

4 solutions

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Rick York · Answer 1 · 2022-12-08T16:06:00

I don't have an answer for you because there isn't enough code posted to have one. I recommend that you check out some sample code to see if you are overlooking anything or just doing something incorrectly. Here are a few samples I found, two of which are here :
A C++ Wrapper for TWAIN[^]
A Copy Utility using TWAIN[^]
TWAIN sample Data Source and Application[^]
Hopefully one of them can help you.

Dave Kreskowiak · Answer 2 · 2022-12-08T17:59:00

Solution 2

Take a look at m_dwRef assert in ~CCmdTarget[^]

It seems an object is not being released somewhere in your code, for whatever reason.
because m_dwRef is greater than 1 - Google Search[^]

Posted 8-Dec-22 17:59pm

Dave Kreskowiak

steveb · Answer 3 · 2022-12-09T01:43:00

Solution 3

Assertion on

ASSERT(m_dwRef <= 1);

Means just one thing: You forgot to call Release() prior object was destroyed

Posted 9-Dec-22 1:43am

steveb

merano99 · Answer 4 · 2022-12-09T08:58:00

Solution 4

There is a hint that different versions of MFC combined in one project may have led to a similar problem.
m_dwRef assert in ~CCmdTarget[^]

Posted 9-Dec-22 8:58am

merano99

Ccmdtarget() assertion failure

4 solutions

Solution 1

Solution 2

Solution 3

Solution 4

Add your solution here

Preview 0

Ccmdtarget() assertion failure

4 solutions

Solution 1

Solution 2

Solution 3

Solution 4

Add your solution here

Preview 0

Existing Members

...or Join us