I have some managed Visual C++ project which uses/links to an unmanaged DLL and serves as sort of a interop proxy between the two worlds, with some additional bells and whistles. It all works fine, the problem is referencing and deployment. When proxy project compiles and links it produces a managed DLL and pdb/xml. However, the unmanaged DLL is not included automatically. I have added the post-build xcopy command to dump it in the output and now the output has the file.
However, when this managed project is referenced by a managed client, say a test c# console app, the build process does not transfer the unmanaged DLL to console app output. Only the proxy dll/pdb/xml are there, as if the xcopy/content-of-build is ignored. Simply put the Add Project Reference has no idea that the unmanaged DLL exists at all.
What do I do in the proxy project to make sure that referencing app collects the unmanaged DLL as well? Is there some manifest to be edited/created?
I also want to turn this into a NuGet package and detach project source from the clients. What can I do there to make sure unmanaged DLL is included, and subsequently deployed with user app?
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I have a source file written in C++, performing some simulation. I would like to create a user interface for this in C#. How can I have both C++ and C# in a single Visual Studio solution?
What I did so far was I created a .NET C# project and solution, and then a native project as a DLL library. I have marked the C# project as "Depends on" the C++ dll. I have provided the necessary dllexport directives and imported using DllImport. Everything compiles fine, but when I execute the application, the dll is not found:
Unable to load DLL 'xxxx.dll': The specified module could not be found.
It is no surprise the DLL is not found, as the application is run from its output directory and the output directories are different for the C# and C++ projects. I do not want to write an explicit path as my import like `"..\..\Debug\xxxxx.dll".
Is there some common way how to structure a solution containing native a Dll and C# app so that the C# app can call the native Dll?
If you know that after deployment your C++ DLL will be in the same folder as your C# DLL (or executable), then on simple way to solve the problem is to use the PostBuild event (Project properties, Build events).
You can add a copy command that will put your C++ DLL into the C# output folder.
I found a very comfortable way, which might have some unexpected drawbacks, but I do not see any so far: I can enable CLR for the C++ DLL project, making it "mixed", even if it in fact does not contain any managed code, and then the project building it can be made a Reference in the C# .NET project.
To make the project mixed mode set Configuration Properties / General / Common Language Runtime Support to Common Language Runtime Support (/clr).
After this the build system copies the DLL into the application output folder automatically.
i have received a wrapper class for a C++ unmanaged code, which i need to add to my web project and call through c#.
1) in a c# desktop application project
When i'm adding references i can only add the wrapper dll. cannot add the unmanaged dll. i think this is not a issue. Then when i'm buliding and running it gives an error saying
Could not load file or assembly 'AskCmnWrapper.DLL' or one of its dependencies. The specified module could not be found.
So then i manually copied my unmanaged dll to the bin folder . It worked fine
2) in a c# web application
i got the same above issue. manually copied my unmanaged dll to the bin folder when i'm trying to run it with iis express (through vs2012) . but it's not working. Is there any special configurations to be made when running unmanaged dll/wrappers in web applications?
please guide me.
thank you.
Chances are you are missing some of the required C++ redistributables or other dependencies. Run Dependendy Walker on your native DLL to see which ones are are missing.
Ideally, you want to make a C++/CLI project which contains the source code of the native library you are wrapping, and write a managed C++/CLI wrapper on top of it, in the same project. This way only the "wrapper" (containing the native code) will be required in your folder.
If you don't have the source, and you can not statically link the library into your C++/CLI project, you will need to have both the wrapper DLL and the native DLL in the directory at run time, as that's when they will be linked.
On a .NET project, I have a couple of functions imported from native DLLs.
Currently to add the native DLLs to the project, they are copied to the root of the C# project and their property Build action is set to Copy to output directory.
Is there a better workflow for bundling native DLLs?
One option, which is particularly useful if you want single exe deployment, is to embed the DLL(s) into your manifest as Resources. This is a similar approach to what is often used to create "universal binaries" which can run on either X86 or X64 platforms from a single file. In that case you embed the 64-bit version inside the 32-bit version and extract it at runtime when needed. You can see that in action with the Sysinternals binaries.
In your case, you would embed a native binary within the managed executable, then either load it as an IO stream at runtime or extract it and reference it from the extracted path. In either case, you never have to worry about "losing" the resource because it's part of your project.
If you decide to go that route, the answer to how to do it has been provided several times over. Here's one such question:
Embedding unmanaged dll into a managed C# dll
I have three projects,
One is a VB6 project which compiles to an EXE.
Another is also a VB6 project, which compile to a DLL.
And the last one is a .Net (2010) project which compiles to DLL.
The DLL from .Net is referenced in my VB6 DLL project.
And the resulting VB6 DLL project is reference in my VB6 EXE project.
In this scenario, how can I debug my .Net DLL project?
It is failing (or not able to debug) in both cases, even if I attach the (VB6 DLL) process to my .Net DLL Project, or I setup the ‘start external program’ to my VB6 DLL project on .Net DLL Project.
Do I have to change the reference (.Net DLL) on my VB6 DLL Project to get it in debug?
All your valid inputs are welcome.
(Please explain the procedures step by step which I need to do)
Thanks in advance.
You should be able to debug the C#.NET dll by setting the start action under Debug to
Start external program
and specify the VB6 executable as the program.
I know this works as I use this to debug a .NET/C# plugin for an old VB6 application.
It shouldn't matter how many other dlls (.NET or otherwise) you have to go through to get to the code you are trying to debug.
ah vb6 :) it's been a long time....
basically, you can't debug .NET code within VB6 IDE.
However, nothing stops you from creating a .NET test project to unit test the .NET dll. And that's what you should have done prior to reference it in VB6.
If you need to track down a specific issue, another way you can use is to write debugging infos to a file/database/event view/... when the dll is in debug mode, like which functions were called, parameters, stack trace...
This might not be correct, but I believe VB 2010 uses what? .NET 4.0, right? VB6 was created in like...1994 I believe, so it would be <= .NET 1.0. The binaries would more than likely be incompatible.
Premise:
Wrote a COM-callable wrapper (CCW) written in C# to be called by VB6 code.
The C# code has .NET libraries (third party) that it must utilize.
The wrapped C# class instantiates fine, raises events properly, takes method calls properly.
Problem:
The VB6 code, when running the C# code, gets an error when the C# code attempts to access the additional .NET libraries mentioned above.
Process tested:
C# wrapped code completed.
VB6 code written, references the COM dll created.
"File not found..." error received when the C# code tries to access the .NET libraries from inside itself.
Copied the third party .NET libraries into the main folder of the VB6 code (also into system32 folder).
Still "File not found..." error.
Wrote a C# Windows Form test project. Referenced the C# wrapped code.
Received the same error as the VB6 code.
In C# Windows Form test project, referenced the .NET libraries used by the C# wrapped code.
The program ran just fine.
Conclusion/Question:
Can VB6 call/use a com-callable wrapped C# program that references other third party .NET libraries?
I've done this with tons of third party libraries and as long as the third party library DLL's are in the same directory as your C# DLL's there shouldn't be a problem.
Copying them into the same directory as your VB6 code will do nothing, the effective directory of VB6 code when running the in VB6 debugger is %ProgramFiles%\Microsoft Visual Studio\VB98, so the code running will have no visibility of that.
The system32 directory has nothing to do with DotNet dll's (the only DLL's they would affect is PInvoke'd dll's and you say you add a reference so that isn't the case).
Adding the third party library to the GAC should fix things, however that is not necessarily possible/easy due to the need to sign the DLL. So just make sure the Libraries you are referencing are in the directory of YOUR library and that VB6 is actually referencing that version of your library (Debug/Release whatever what last compiled). You may want to hand RegAsm the library to make sure the correct library is Com Registered.
So to sumerize, suppose your source code looks like this:
c:\projects\vb6project
c:\projects\c#project
And your project is set to Debug, the third party libraries should be in:
c:\projects\c#project\bin\Debug
When you actually want to distribute the application, make sure that ALL the libraries are in the same directory as your VB6 exe.
This will mirror somewhat the answer by Kris Erickson.
First, for my usage which solves these problems, I did not use the GAC. Assuming that my VB6 application is in c:\program files\mycompany\vb6app.exe, I placed the COM-friendly .NET dll (lets call it net4vb.dll) in the folder with the executable. I then regsiter that dll there with RegAsm using the /codebase option. Finally, I place the .NET assembly that I'm wrapping or using (lets call it purenet.dll) in that folder as well.
At this point, vb6app.exe should run with no errors.
It is important to note that if you select the "Register for COM Interop" in Visual Studio then it will overwrite the registration you did above. So do not use this option. Stick with the command-line tools only for this.