OpenPop.net called from unmanaged code (causing GPF) - unmanaged

I would like to create a C# managed x86 DLL wrapper for OpenPop that I call from my unmanaged (C) code.
I have done this for other products in the past using the NuGet "UnmanagedExports" package which seems to work well.
I tried doing this with the OpenPop.net package but I get a GPF as soon as I call "client = new Pop3Client();". If I remove all calls to OpenPop, the DLL loads and returns properly.
Furthermore, I am accessing OpenPop from within a try/catch structure yet it still fails with a GPF (instead of catching this error).
I installed the latest OpenPop.net package v2.0.6.1120 and I am targeting .net v4.5.2 (I also tried v4.0 with no difference).
Can OpenPop.net be used like this in conjunction with the UnmanagedExports package? If so, any suggestions on how I might debug this?
Thank you!
(I realize that this is free software so support is no expected so I am more than happy to pay for support if required)

I found the problem... I was not copying the OpenPop.dll to my application folder where my DLL is loaded. Once the file was available, the GPF no longer occurred. Too bad this was not able to be trapped by the C# exception handler.

Related

How to find out in unmanaged code if it is running in managed context

I am writing an Excel VSTO add-in. This add-in loads and runs unmanaged code.
In the startup code of the unmanaged dll, an invisible window for request handling is created. This function call causes a managed exception (LoaderLock) and if I remove it, everything works. I want to avoid creating an extra version just because of this. Is there a way for the unmanaged code to find out at runtime whether it is running in a managed thread? In this case, I could add a runtime check. The window is only needed in a fully unmanaged environment.
Note 1: The issue only occurs in this Excel add-in; a stand-alone managed console application using the unmanaged dll does not show this problem.
Note 2: I know that there are many things that should not be done from within DllMain. What I am doing has been working for more than a decade in managed and unmanaged environments and I want to keep code changes as small as possible.
Checking if mscoree.dll has been loaded has done the trick for me:
if (::GetModuleHandleW(L"mscoree.dll") == nullptr)
This: Checking if a WIN32 / Unmanaged DLL is loaded from a COM module on runtime and this: What does it mean when code "runs on" the .NET CLR? helped.
As exposed in the comments below, this does not tell which type of thread has loaded the dll, but only whether there is any managed component in the process. A more precise check would still be preferred. For the moment, I can live with this solution.

ros::init(...) throws an error - Windows roscpp

I'm trying to use ros in cpp with Visual Studio 2012. I wrote the publisher and subscriber tutorial (http://wiki.ros.org/ROS/Tutorials/WritingPublisherSubscriber%28c%2B%2B%29) and first, I configure the project as says in the guide (http://wiki.ros.org/win_ros/hydro/Msvc%20SDK%20Projects).
Then i compiled an linked the publisher, but when I tried to run it, ros::init(argc,argv,"talker") throws an exception... The console says that I ROS_MASTER_URI is not defined but I've got it defined
There are 2 images here:
https://www.dropbox.com/s/o12m0l38gaxiugi/error1.png -
https://www.dropbox.com/s/ocdmf0wj6rj0962/error.png
Can anyone helps me?
Thanks in advance
So, I had the same issue, although I didn't set the ROS_MASTER_URI globally.
I managed to get around this specific issue by adding
ROS_MASTER_URI=http://localhost:11311
to the debugging environment variables (Project->Properties->Configuration Properties->Debugging->Environment).
However, after implementing the above I got an uncaught exception (Unhandled exception at 0x768bc41f in ros_demo.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x0028f0e4..).
That went away when I built, compiled and ran the project in release mode (which matched my ROS SDK build).
I got the idea for the release/debug build from here:
xstring isn't an OSG specific object, so the error is elsewhere in the
3rd party dependency chain. As I know nothing about your OS and
software setup I can't speculate what this might be.
In general though this type of error could well be a linking issue -
for instance Visual Studio is hopeless at handling different libs
being built debug and release and will crash randomly.
That was fun to discover..

QBSDK Distribution for VB6 App

Ok, I went through great lengths but I finally got my integration to quickbooks working on my VB6 application. It works perfectly on my build machine. I actually installed the qbdsk11 on my build machine and worte and tested the code. The ONLY new reference in the project is the QBFC11.dll.
So, I added the QBFC11.dll to my innosetup, told it to do a regsvr on the dll, and hoped this was enough.
NOT.
First, during install, I get a failure to register the dll. Apparently, this DLL isnt meant to be registered?
But the .DLL was put in Windows System32, so I tried my program anyways...
NOPE. Doesnt work. I get a runtime 91, about an object variable not set. Which makes sense, if it cant create the object.
So, for grins, I moved a copy of the .DLL into the program folder, next to my executable.
Same thing. Runtime error 91.
So, i then grab the whole qbsdk11 installer and install it on this machine. I figure I can make it an additional download for people who want to use this extra functionality.
But no, even with the whole SDK installed, I still get the same runtime error.
I have not been able to find any CLEAR information on how to proceed. I'd prefer for this to be part of my base install. But apparently something still just isn't right.
What did I miss? How do I fix this? I don't even know what to try next.
If you're using QBFC11, you must install the QBFC11 redistributable components with your application. You can find instructions on how to do this in the QBSDK Programmer's Guide in the section titled Redistributing SDK Components With Your Application, subsection Using Installers and Merge Modules.
The most likely cause of the runtime error you're currently getting is the manipulation of the QBFC11.DLL that you did before you installed the SDK. I would start again with a clean OS image so that you can get the proper procedure down.

createObject in VB6 does fails when running exe

I have a VB6 program which tries to run a DLL written in C#.
This DLL has a COM interface so I can create an object of a class in it with "CreateObject".
The problem is that it runs and works well when I run it from the VB6 IDE, but when I make an EXE and try to run it, it throws the exception:
"Automation error. The system cannot find the file specified (-2147024894)."
Why is it happening and how can i solve it?
Look at Project, References in the IDE and look which dll or ocx file belongs to the object you are referencing with CreateObject (the Object Manager might also help to find out).
This dll file must be available when the exe is compiled, too. Usually, you need to have it registered with regsvr32.exe.
A technique I use to figure issues of this type is to open the add reference dialog in Visual Basic 6. I scroll the list of available COM Libraries and see if the problem DLL is listed. If it is then CreateObject should work, you should be able to assign it do a variant variant and use late binding to access it's members.
In addition try temporally set a reference to the variable and instead of using CreateObject use the = New and see what error messages, if any, it gives you. Generally I found them to be more informative then the ones thrown by CreateObject.
Finally it would help if you post the reason why you are choosing to use CreateObject instead of setting of a reference. If the DLL is a known object that will be continually used by the program then a reference should be set and early binding generally used.
Finally it may be that the error is resulting from a dependency of the C# COM DLL not the DLL itself. If for example I was to take a Com Library and properly register it but it relies on the COM Library Widget2000 and it NOT registered then it will throw the automation error. Especially if you are testing the EXE in it's installed environment and not the environment in which you complied it.
For example suppose I have a CAD program written in VB6 and I have source tree that begins with MyCAD. THe exe is in MyCAD/MainEXE and the shape library is in MyCAD/ShapeLibrary. I run the IDE everything is fine. Then I make my setup and goto my test machine and install it and it error on the creation of shapelibrary.
The first thing I would do it check if MainEXE will run straight out of the MainEXE directory of my source tree. That test will eliminate whether it is a install issue or a quirk of the IDE vs complied version. Then I would look at the setup and see what not being registered. Also look at either the source for the C# library or the setup for the library and see what dependencies it needs. Since it a complied COM DLL you should be able to use a dependency walker tool to see what COM references it needs. Finally make sure the correct version of the .NET framework is installed.
If you are compiling the C# DLL on your test machine - make sure you have ticked the register for COM Interop setting. If you are not compiling on the same machine you need to run RegAsm with the /codebase option.
try compiling it as an installer and include the dll/com that you use in the compilation of the installer package so that the dll/com that you use will be include in the compilation of your exe.., and install it in the windows not just copy past it.

How to fix "Unexpected error (32801)" when compiling VB 6 program?

I have to maintain an old VB 6 ActiveX DLL called by another third-party program for which I have no sources. This DLL works and compiles fine against the API of said program for about 6 years and 3 major versions.
But now when I try to compile the DLL against a new major version the mentioned error occurs. It seems the error occurs before "my" code is called so there´s no use debugging or logging. The only remedy was to compile w/o binary compatibility which is no real option. My Google search turned up quite some people with the same problem but no solution.
Does anybody here know how to fix this issue ?
I finally figure out how to diagnose VB6 error 32801 in a systemic way.
My theory is When the VB6 compiler is creating a project or binary compatible library, the compiler decompiles the type information from the referenced library. Error 32801 occurs the source code's type information is not the same as the referenced library.
There is a tool called OLEView. This tool can decompile the COM type information into an IDL text. What I do is decompile the referenced library in to IDL and take the last good build of the failing library. Most times it is a build server version but the build does not work on a developer workstation. Decompile the last good build. Use a text comparison tool, like WINMerge, and find the differences between the type libraries. The differences make it easy to track down the problem.
Depending on the difference will determine how to correct. Mitigation can be done by either correcting the reference DLL, or by source code correction, or source code references.
It sounds like one of the types in the interfaces defined in your new DLL is different from one in the previous DLL. I'm deducing you use types defined in the third party program in your public interfaces of your DLL. It sounds to me like the third party has changed the definition of one of the types but kept the name and GUIDs the same. You could use something like OLE/COM Object viewer to check whether that's true. If it is true then you can complain to the publisher of the 3rd party program. Do you have enough political power to succeed?
Bruce McKinney, the guru who wrote Hardcore Visual Basic 6, ran into the same issue with a structure in a type library, where he changed some of the member types. The only fix he could find was (essentially) to break binary compatibility - and that's after some correspondence with the VB6 compiler team, who he knew fairly well. I don't think anyone else could do better.
There is a discussion about this error on devx.com that seems to indicate that the problem stemmed from Microsoft's Scripting Runtime (scrrun.dll).
FileSystemObject compatibility Unexpected error (32810)
Does your DLL reference that library? If so, can you remove the reference (e.g., replace FileSystemObject functionality with intrinsic VB file handling functions and/or API calls).
Are any of the files associated with the core project being compiled marked as Read-Only (i.e. not checked out of SourceSafe or similar repository)?
*.exp
*.vbw
*.lib
---------------------------
Microsoft Visual Basic
---------------------------
Unexpected error (32810)
---------------------------
OK Помощ
---------------------------
This the message I was getting trying to reference in VBIDE an old OCX that has been recompiled recently.
After somewhat long research the offending lines of code causing this error appeared to be
Property Get MouseActivate() As BookmarkEnum
Just changed this to
Property Get MouseActivate() As Boolean
. . . and the error was gone.
BookmarkEnum is an enum from ADO. Our build server is Server 2003 and my dev machine is Win10. The project references ADO 2.8 but apparently this typelib has some differences on Server 2003 vs Win10

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