I've got a code snippet of c# that I've been trying to translate into vc++, but I'm having some difficulties. So, I'm wondering if it is possible or advisable to mix c# and vc++; that is to say, can I call my c# function from vc++ and vice-versa. If so, are there tricks to it? If, not, why?
Calling C++ code from C# is easy enough and you should be able to find plenty of articles on Pinvoke and other types of interop.
For calling your C# code from C++ - if your C++ app is managed then you should be able to directly reference the C# assembly from your C++ app and use it as normal.
If ypu C++ code is not managed then you will need to use some sort of interop to allow your C++ assembly to call C# code, the only way of doing this that springs to mind is COM.
Try some of these links for more information on COM interop with C#:
http://www.codeproject.com/KB/COM/COM_DOTNET_INTEROP.aspx
http://www.codeproject.com/KB/COM/nettocom.aspx?df=100&forumid=14076&exp=0&select=864859
Is the VC++ app managed? If so, you could create a C# DLL, use it from your c++ app, and if you so desire, ILMerge them into a single EXE.
If you want to mix the two, I'd start with C# as the base project and then register an unmanaged (C++) DLL in your C# project. That way you can combine the reliability of the managed C# parent application with the speed benefits of C++ in any processor-intensive methods you might have.
Related
Is it even possible to create GUI layer in C# and rest of application in C++? If I am not wrong one of antyvirus software had GUI made in Delphi. How it could be done ?
You have several options for doing it, including:
Use P/Invoke to call into the C++ DLL from C#.
Expose a COM interface from the native code, and call it from C# using COM interop.
Write a native Windows service and call into it from managed code.
Use C++/CLI to write a managed library in C++, which you can easily link to from C#.
If you're starting from scratch, option 4 is probably your best option. (Aside from just writing the whole thing in C#, that is.) The first three options all involve some additional wrangling and overhead, and probably aren't worth the hassle if you don't have a compelling reason such as needing to interact with an existing native library or having some need for a service-oriented architecture.
If you write your business logic in C++/CLI, and your UI in C#, it shouldn't be a problem. If you want to write in pure ANSI C++, you might have to write C++/CLI wrappers around the objects you want to expose to C#.
write the app logic in c++ dll, then use pinvoke from c# to talk to the dll.
See this answer. It seems to answer your problem
My question is what's the best way to create an inteface with C++ code.
Basically so far I have a console project in c++, that works as I expect to, but I now want to make a GUI for it. The choices to me seemed to be:
Make a dll of the c++ project, and then make a C# form which uses the dll to do the logic.
Same as 1 except with VB.
Use QT or something eqvilent and make the inteface in the same project.
I've been trying option 1 for quite sometime. I made the library I believe successfully by making a library project in Visual Studio 2005. I then put it in my c# project but I then had a problem of being able to instantuate my class, but the c# project couldn't see my methods.
The only fix I could find to this was to use the ref keyword. The problem with this was then not being able to mix managed and unmanaged code and trying this on one of the larger classes produced about 250 errors.
Option 2 i had the same problem with.
I'll start option 3 if I have to, I just wondered if I was missing anything fundamental or any suggestions in general?
Cheers for reading.
You absolutely can use C++ code from C#, but if it's unmanaged C++ code, you have to delve into the realm of pinvoke to call your code.
If you're attempting to leverage an existing C++ library from .NET, one of the easiest ways to do this is by using C++/CLI as a wrapper around your unmanaged library. C++/CLI compiles into .NET bytecode, but features lots of automatic unmanaged interop. A phrase that's often floated about when using C++/CLI unmanaged interop is "it just works". It's an accurate phrase.
Once you have a C++/CLI wrapper for your unmanaged code, C# should be able to see everything exposed by your C++/CLI library.
I would like to add my C++ application a C# .NET GUI .
My C++ application is very simple but I have a some Pointer and Reference .
What is the Best way C# will recognize this pointer and Reference?
There are several ways, here are some, and it depends on your taste and on your project.
a) Use COM interop, if your C++ project is written in COM.
b) Use COM interop, you can write COM wrappers to your C++ application and use it from C#.
c) Use C++/CLI, that is, convert your project to become a Managed C++ application and create managed classes in C++ that use your C++ code.
You can also write a managed C++ dll that loads your C++ dll or static library.
d) Use P INVOKE C calls, exports DLL C functions from your C++ code that work with your C++ class, call the C functions from C# using [dllimport] attribute.
You can use type IntPtr and the better and safer SafeHandle to express pointers and references.
All ways have good things and drawbacks, but every listed tehcnique need a "middle layer", you cannot call C++ code directly from C#.
If I understand correctly you want to use the functionality written in C++ program in a C# based UI application.
You can do this by creating a C++/CLI based dll. C++/CLI can call C++ code easily and C# can easily call C++/CLI code. In this way you can use functionality written in C++ in a C# based program
For all possible ways see this post
Is there a way to call c# dll from c++ unmanaged application without COM usage?
You can do this using Reverse P/Invoke - example and discussion here.
It is actually possible to disassemble, modify the IL, and reassemble it with exported functions. I messed with this a few years ago, and created an application that would disassemble a dll, provide a list of functions that could potentially be exported - allowing the user to select them, then re-write the IL and reassemble everything. Then, I could call directly into the dll from unmanaged code...or p-invoke into the dll from managed code (not really practical, but interesting nonetheless).
Surely there is a reason that this isn't supported in the .net languages themselves (even tho it is supported in MSIL). I wouldn't use this in production:
Dead link:
http://www.csharphelp.com/2007/03/exporting-managed-code-as-unmanaged/
Wayback Machine:
https://web.archive.org/web/20140213030149/http://www.csharphelp.com/2007/03/exporting-managed-code-as-unmanaged/
I might be a bit late, but check this out.
Using this little msbuild task, you can create a C# library that can be called as if it were a native DLL. (e.g. write plugins for apps that require them to be native dlls)
Oh and don't forget to use the project template, which will setup everything for you.
Your only option really is to either use C++.net or create a C++.net wrapper for it that exports what you need.
Calling C# code from C++
Is it possible to use a C++ .lib file from within a C# program?
There are plenty of ways. Read about "interop" in MSDN..
One way is to expose the lib as a DLL, and then use pinvoke to call these functions from a C# project. That limits you to a C-style interface, though.
If your interface is more complex (e.g. object oriented) you can create a C++/CLI layer that will expose the lib's class structure to your C# program. This means you'll have to create a managed C++ (or C++/CLI as it's now called) project; then design an interface in managed code that will be implemented by calls to native C++ (i.e. your lib).
Another way of doing this is by wrapping your lib with a COM interface. But COM's a pain, so I wouldn't...
Not directly. You can create a C++/CLI assembly that consumes the lib and then access that from C#, or you can wrap the lib as a DLL.
What you need is a managed wrapper (C++/CLI) around the native C/C++ library that you are working with.
If you are looking for any C++/CLI book I'd recommend Nishant Sivakumar's C++/CLI in Action
Already answered to wrap it but here's an example . Good luck!
I would take a look at swig, we use this to good effect on our project to expose our C++ API to other language platforms.
It's a well maintained project that effectively builds a thin wrapper around your C++ library that can allow languages such as C# to communicate directly with your native code - saving you the trouble of having to implement (and debug) glue code.
No. You can only use a full .dll from a C# program.
That depends, do you have any limitations on this scenario?
If you have a lib file, it should be possible to first compile it into a DLL file, secondly exposing the functions you want to call in the DLL interface, and thirdly, call them using C# native methods (have a look at pinvoke.net on how to do this bit).
you can't use a lib, but like the others said, you can use it if you wrap it into a dll.
swig can take the headers of your .lib, and if they are not too complex it can generate the dll for you which you would then call with a pinvoke from c# which would also be generated by swig.
if your library is complex and has reference counted smart pointers everywhere, you should find an alternative.