I am trying to call a dll file from c#
The dll file is made from a java application using ikvm and for now all the code does is print hello world.
How do i call the dll file in my c# code and is it possible to create an application in java that will return a boolean value to my c# code?
Thanks for your time.
I'm not sure I understand what you're trying to do, so apologies if I'm misreading. IKVM should translate your java code to a .NET dll or executable. After the "translation" you should be able to use the .dll more or less in the same way as you would with a "native" .NET code.
If your java application has a main method that prints "hello world" on the console, you should have converted it to a .NET executable (.exe) and not to a dll.
After converting it to a .exe (and assuming you're running it on Microsoft .NET on a windows system) you should just execute it.
As for the second part of your question, you can also create a dll (converted from java) that returns a boolean and consume it from a C# application.
See this tutorial for two examples of (pretty much exactly) what you're doing.
using System.Runtime.InteropServices;
You can then use
[DllImport("myjavadll.dll")]
Then add the dll as a reference by right clicking and navigating to it in the reference folder.
EDIT:
Here is a link that calls a C++ dll to C#. You may be able to work it out.
Call another languages DLL
EDIT: I have had issues adding DLLs as references and was forced to add as a resource. I believe this was because I was working with a sys32 dll.
Here is an old post by where I was trying to work out some DLL import errors. Maybe itll be helpful if you encounter some problems.
Old Post
Related
I currently have a C# DLL project in Visual Studio.NET, and I need to be able to use it in creating a C++ DLL. However, I can't seem to figure out how to include the C# library or file in C++ and then use it.
I've tried compiling the C# DLL, but I can't reference it in C#.
I've also tried to include the .cs file in C++. This seems to work since the namespace is coming up now, but I can't seem to use any of the actual functions in the C# file.
Please let me know. Thank you!
I have created a C++ application which uses a C# dll following the link as shown below.
http://support.microsoft.com/kb/828736
The application works fine on my development PC , but when I tried to run it on another PC , it fails.
The only way to make it work is to recompile the C# dll on that PC and run the Regasm command again on that PC to work .
Is there a way to build my C# dll in such a way so that I do not have to do this every single time on every PC my application is deployed to ?
What regasm does is generate a COM wrapper for your C# dll and then registers it as a COM object.
You do not need to recompile though, once you have a dll you can register it on the target PC using regasm.
The main other way to call a C# dll is to write a C++ .net program using the C++/CLI system from Microsoft. This is basically a way of creating .NET programs using a superset of C++ (hint: its not C++, which is a shame as the old managed extensions it replaces was much more transparent for this task). As its not 'true' C++ you'll end up with a .NET binary instead of a C++ one, so be aware of this. One aspect is that you could write a C++/CLI wrapper to the C# dll and call that from your C++ program, this is probably the preferred way of creating a bridge between the systems.
I did this, and it worked, copy and paste the code on cmd
%SystemRoot%\Microsoft.NET\Framework\v4.0.30319\regasm.exe MyAssembly.dll
Kindly vote if it works for you. :D
I've read many solutions to the issue of using C# code in a C++ project, including this one: How to use c# code in C++ project
I've also read this, and one answerer says Compile your C++ code with the /clr flag. With that, you can call into any .NET code with relative ease.
Does this mean that I can use C++ & C# code together, within the same project if I append the /clr flag?
I'm a little confused by this, and it'll just waste time if I went the long route of converting the C# project that I'm trying to use parts of to C++, if doing so isn't actually needed.
Basically, I answered my own question on a different topic a couple of days ago without realising that the actual code of the sample project is C#:
Obtaining Current Network Rate
Can anybody give me a firm clarification to whether I understand this correctly (that I can use C# code in a C++ project with no issues, apart from the /clr switch being required)?
I'm not sure if SO is the right place to ask a question like this, so please tell me if it isn't instead of downvoting with no explanation.
Thanks.
Edit
Forgot to mention that this is a C++/CLI gameserver application DLL on Windows. If it matters, it is used on only Windows Server 2008 R2 and Windows 7.
If you use C++/CLI, then you can add references to other .net assemblies, but you do not mix C++ and C# code in the same project. What you would do is to create a new project (or add an existing one) in your solution using C#, and then add a reference to it in the C++/CLI project.
The drawback is that you need to marshal between C++ and .Net types (std::string vs System::String^), and you also need to learn the additional syntax used by C++/CLI (^, gcnew, etc.).
Further reading: Pure C++: Hello, C++/CLI
It means, that with the /clr switch, you can access assemblies (DLL or EXE) written for the .Net framework. Because such assemblies can be created with any .net language (including C#), you can use "code" written in C# from within C++, but it doesn't mean that you would be able to write C# in C++ project. Unfortunately - you can't.
You need to make a C++/CLI project in visual studio.
C++/CLI is a bit different to C++, because there is the managed stack, so memory is managed and you can avoid memory leaks (garbage collection).
Simply create a C++/CLI project and click on propietys and add a reference to your C# project, it should work :D
http://www.codeproject.com/KB/cs/ManagedCOM.aspx
I have written a library in C that I want to be able to be used in C#, C++, and Python (other languages would be nice, but not necessary for now). The library was developed in Linux and I have been able to compile it on Windows via MinGW. The problem I am having is when trying to add the .dll as a reference in a Visual Studio 2010 solution. The error I get is:
A reference to 'C:\path\to\libmylibrary.dll' could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component.
I have spent some time trying to see if I am compiling the DLL incorrectly, but don't see anything glaring out at me. Some references I've used are this, this, and this.
If more information is needed I can provide some compilable example source code.
There are 2 ways to add a "DLL" to a C# project.
If the DLL is a CLR Assembly, meaning it is managed code that adheres to the CLR, then you can add it as a "reference".
If the DLL is NOT a CLR Assembly, you can load the code manually using the P/Invoke structure. There's a lot of online documentation on P/Invoke. It is messy, but it works. You need to declare each DLL entry function using the [DllImport] attribute, and load the DLL manually. Search SO for p/invoke.
Based on your error message, you are trying to load a plain DLL as an CLR DLL. That means you'll have to figure out how to use P/Invoke.
I am supposed to be updating a piece of software for someone. Originally written in VB 6 I want to import it into a .net c# project. My question is, I don't want to have to lay out all the forms again and I am wondering if, or how, I could import them into c# project. They originally come with the .frm extension and c# forms are .cs. I tried 'add existing item' to the project but obviously that didn't work, and I tried a couple of other things. Is there a way of importing them that would work? I just need the layout, not worried about the underlying code or anything as this will all be re-written.
Thanks, R.
You can utilize the VB upgrade wizard, but that will only get you to VB.NET (potentially as there as some things that cannot be upgraded). Or you can compile your VB6 app to a COM dll... then call the COM dll via interop.
As already mentioned, you can migrate to VB.NET first. You can copy and paste controls from one project's form to another's.