Sorry if this is an obvious question, but I'm new to C# and am trying to use 2 dll's for a project. Where do I put them?
I tried to add SoundTouch.dll as a reference in an empty C# project, but Visual Studio said to make sure that the file is accessible and that it is a valid assembly or COM component. I was suggested to put the dll's into the \bin\debug path, but where is that? Thanks for your help.
Each project should have it's own \bin\debug (and \bin\release) directory structure under it's project directory, but they will not be created until you Build the project. As for the invalid assembly, it sounds like your dll has either become corrupted or is not a valid .NET assembly.
Edit: Looking at the SoundTouch website, someone has already created a wrapper for this dll suitable for use with C# and it can be found here
If your DLL is a .NET or COM DLL, you can simply add a reference in Visual Studio. For details on that procedure see
http://msdn.microsoft.com/en-us/library/wkze6zky(v=vs.110).aspx
If the DLL is a Win32 DLL (does not expose a COM interface) you can interface with it via the Platform Invoke (P/Invoke) mechanism.
http://msdn.microsoft.com/en-us/library/aa288468(v=vs.71).aspx
When using P/Invoke the DLL must reside in a location that can be resolved by the .NET runtime, and you use the DllImport attribute to "pull" entry points from the DLL into your C# code, e.g.
[DllImport("msvcrt.dll", EntryPoint="puts")]
.NET will search for the Win32 DLL in the same directory where the .exe is located. If you build under Visual Studio, a folder will be created under your project folder
bin\debug
for a debug build, or for a release build
bin\release
Related
I am in the process of creating a library to be used in Windows desktop applications. The core part of the library will be a C/C++ DLL that can be used in Win32 applications or other C/C++-based apps. I'll just call it libtest.dll for easy referencing here. I also want to make it available to Windows Forms applications (C#), so I am creating a C# class library (DLL) as a wrapper around the C/C++ library using P/invoke (DllImport) to call into the C/C++ code. I'll refer to this library as Test.dll.
Additionally, I have a Windows Forms project set up in Visual Studio for testing that depends on the C# class library project. The C# class library depends on the C/C++ library project. However, for Test.dll to find libtest.dll (in the DllImport statements), libtest.dll needs to either be in the same directory as Test.dll or in one of the DLL search paths in the system.
To make this easy when debugging in Visual Studio, I thought adding the libtest.dll project as a reference to the Test.dll project would automatically copy libtest.dll into the output directory of the Test.dll project. When I add the reference and then build the solution, the reference ends up broken and the libtest.dll file is not copied into the output directory of Test.dll.
When I add the reference to the Test.dll project in Visual Studio, the properties of the reference look fine:
"Copy Local" is set to True
The path is correct
"Resolved" is True
After building, however, the reference itself has a warning icon on it, and the path is now empty and "Resolved" is False. Any idea why, or how to fix this? How do I set up the project reference between these two library projects so the C/C++ DLL gets copied into the output directory of the C# class library project? I have verified that the build order of the two projects is correct: first libtest then Test.
I am trying to reference a native dll from an asp.net 5 project using pinvoke. The recommended solution is to wrap the dll in a nuget package and reference that. However I am also developing the native dll, so it is impractical to constantly create new nuget packages when I make changes.
If I have the native dll location in the path variable it is found through pinvoke and works fine. But I would like a solution which is contained in the Visual Studio solution so that other developers could download the VS solution and have it work without changing the path variable.
I tried using the bin syntax as described in this topic:
How do you add references to locally created NON ASP.Net 5 dlls to an ASP.Net 5 project
but that seems to only work for managed assemblies as I get an error stating that the assembly manifest cannot be found.
Thanks
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.
I wonder where dll files are stored in Visual Studio and whether its the best way to keep them there or consolidate elsewhere for the following cases:
1) My solution includes a c# library project which other projects in the same solution reference to. My understanding is that the library project stores the dll in its own directory /bin folder. So do I need to establish the reference to that library by pointing to the dll in that external folder? Problem is that this dll should later be shipped with the projects referencing to the dll file. Will the projects who reference to the dll file create a copy of the dll in their own project /bin folders or how does it work?
2) where should I copy external libraries to that are referenced by projects I like to ship in compiled fashion? Should a dll be copies and referenced to into each project's bin folder that utilizes such external library?
I am a bit confused by how going practice is and could not find straightforward answers in other posts here.
Thanks
If you can set two solutions one for your dll referenced and another for your project that reference them after
create a dependencies folder where you will set all binaries that are dll you need
set path to this dependencies folder on all your projects that will create dll you want to reference
set build order on your solution to first build your dll and after build your project that reference your dll
when you deploy it, make sure that you create dependencies folder
For your information, your application first see on GAC folder (windows\assembly), after see on your current path, and after use PATH environment variable.