I have a C# project A which uses a .net wrapper DLL and a native DLL. I add the .net wrapper DLL to the reference list of project A. Since the wrapper DLL only works with the native DLL when they are in the same folder, the native DLL should be copied to the output directory of project A. I achieve this by adding the native DLL as a content file under project A and set its copy action to copy if newer. This is fine.
If a C# project B has direct reference to project A, VS will copy all dependent files used by project A to the output directory of project B. This means the wrapper DLL and the native DLL will be copied to project B's output directory as well. This works fine as well.
Then I have yet another C# project C, which only directly refers to project B, not project A. It is interesting to see that VS will not copy the native DLL to the output directory of project C, which is what I intend to do otherwise when project C uses the functionality of project B and looks for the native DLL to work with the wrapper DLL, it won't find it.
Can someone explain why VS doesn't copy the native DLL　to the output directory of project C? What is the mechanism of copying chain-dependent files in VS? Many thanks.
Basically reference-chains don't propagate, and it is up to the topmost assembly (the exe, web-site, etc) to ensure that it has everything it needs, either locally or in (for example with managed dlls) the GAC. You will need to add the files to the exe/web-site as "copy to output".
Why not just add the native dll as a reference in project A? This will ensure that it'll always be included when other libraries use A.
Edit: Nevermind, this only works if the dll is a COM or .NET component.
Because there is not an explicit dependency in the project, the builder does not know that those need to be output with the known binaries. What you can do is create a post-build configuration to copy those DLLs to a build destination upon compilation. You can Google how to do that, here's one of the first results that explains how to do this:
http://visualstudiohacks.com/articles/general/customize-your-project-build-process/
Related
I have the follwoing scenario:
C# project A uses an unmanaged dll via p/invoke: [DllImport("someUnmanaged.dll")]
project A is configured to copy "someUnmanaged.dll" to the project bin folder when compiling. This works fine.
C# project B, C and D all reference A. But they do not automatically copy the unmanaged dll. I have to configure each of those projects to copy the unmanaged dll.
So, If another developer wants to use my projectA.dll, they have to know exactly which unmanged dlls to copy, and how to configure their VS project.
If project A is a managed c++/cli project instead of a c# project, I can use /ASSEMBLYLINKRESOURCE "...\someUnmanaged.dll" to tell the compiler to always copy someUnmanaged.dll whenever it copies projectA.dll.
(this is a setting in Configuration Properties -> Linker -> Assembly Link Resource)
/ASSEMBLYLINKRESOURCE somehow annotates projectA.dll, so that when this dll is referenced in another project, visual studio will automatically search for someUnmanaged.dll as well, and copy both during compilation.
How can I get this functionality in a c# project?
We have an app A that has a reference to an assembly B that contains some static methods. Assembly B is in the same Visual Studio solution as app A.
We want the users of our app A to be able to write plugins. They build the plugin (at present) by creating a new Class Library solution in Visual Studio, getting the Nuget Package for app A, and adding a reference in their plugin solution to assembly B, so that the plugin code compiles.
They do not need to test their plugin, which is why the code just needs to compile, although it would be nice if they could debug their code when running it in app A.
Once their code has compiled, the DLL for the plugin is put in a share and given to a different team (bureaucracy I know) who put it with the rest of app A's DLLs.
I would like the plugin DLL to use the assembly B DLL that is with all of app A's DLLs.
When I run app A, the Activator class picks up the plugin DLL and correctly creates an instance, but as soon as one of the static methods from assembly B is called, the plugin throws a MissingMethodException.
Things I have tried:
The plugin solution definitely works fine if you create it and compile it within application A's Visual Studio solution.
App A uses framework .Net 4.5, assembly B uses framework .Net 4.0, I have tried building the plugin with both frameworks without success.
The "Specific Version" of the reference to assembly B in the plugin solution was false in all cases tested.
I would welcome immediate solutions to this problem but also broader architectural suggestions on how to get these plugins to work. I apologise if there is a duplicate question of this, I couldn't find one.
For starters you can use "Dotpeek" to decompile dll and see if the method defination exactly matches.
It's a free software available to decompile dotnet libraries.
If you don't have access to .pdb file then i would recommend using "dotnet reflector",or "IL Spy" it will decompile without pdb files.
Also do make sure you are referencing project in visual studio not the output dll.
I managed to fix my problem as follows:
Although the plugin only directly used static methods in Assembly B, these static methods actually made a chain of calls to various OTHER assemblies.
Instead of just adding a reference to Assembly B in my plugin, I did a Nuget command:
Install-Package -Id AppA -ProjectName Plugin
And this downloaded the latest AppA to the packages folder and added a reference to EVERY dll of AppA.
Like before, it compiled, but this time when I dragged the plugin dll into the AppA bin folder, the plugin code ran without throwing an exception.
I have a C# project which builds a library DLL, myLib.dll. This DLL has a dependency on a 3rd party DLL, dep.dll (which I provide but do not build).
I want others to be able to use my library by adding my project to their solutions and referencing it. Adding my project as a reference automatically copies myLib.dll to the Target directory of their app, but of course dep.dll is not copied with it.
Bear in mind that I have no control over where my project is in their code tree, and the DLL can't know where it was copied from.
The only solution I can see is to force the user to add a build event which copies dep.dll to their target directory. We can't assume users can create environment variables.
This is very undesirable for several reasons (it's not really one dependency - I simplified things, I don't want them to have to be concerned about the dependencies in my project, and it's very fragile - adding an extra dependent DLL to my project would require everyone to update their build scripts).
I can't load the dep.dll directly as I don't know where it is - my build scripts can copy it to the same target directory as myLib.dll but the actual version of myLib.dll they run will have been copied somewhere else.
I also can't make dep.dll a reference directly (probably because it's not a .NET assembly). I just get "Error loading code-completion information for dep from dep.DLL. Format of the executable (.exe) or library (.dll) is invalid".
So is there any way to have the dependent DLL just seamlessly copied with myLib.dll when a client builds their application? [I'm using Sharp Develop if it matters.]
Can you add dep.dll to your projects root folder as a file like a .cs file. Set the Build Action to None and Copy to Output Directory to Copy if newer.
I need to use an external DLL library within my project. When I add the reference to that library, is my project importing it, or is it just referencing the DLL at its location?
At compile time, it is a reference to the dll at that location. However once compilation is done, the referenced assemblies may be copied to output directory of your project i.e. next to your project's dll or exe e.g. bin\Release (configurable). You can control this behavior by changing the "Copy Local" property on the reference.
At run time, the assembly is searched for in multiple places such as; the same directory where your primary executable/assembly is placed. See Locating the Assembly through probing for details.
.NET does not embed the referenced assembly in your exe/dll unless you use ILMerge.
Define what you mean by "import"? Where you think it is imported to? It is a reference. The file gets copied to the output when the reference is told to do that.
When I reference DLLs from outside of my project, I have found that the dll file gets copied into by bin/Debug or bin/Release folder. Then, links are resolved at runtime, so while by .exe can be moved around, I still need those DLLs in my path or else I get a "missing reference" error.
This has bitten me a few time when running a C# project via mono on a Linux distribution until I remembered to copy the .dll files over as well. Then it worked fine.
One solution (the.sln)
One C++ project (mycppproject.vcxproj in 2010or mycppproject.vcproj in 2008) which compiles a native DLL exporting some function(s). In debug this builds c:\output\Debug\mycppproject_d.dll and in release this builds c:\output\Release\mycppproject.dll.
One C# console application (mycsharpconsole.csproj) containing PInvoke calls into the DLL.
All compiles fine.
When I build, I would like to be able to add a reference from the csharp project to the cpp DLL project so that it can copy the appropriate file from the appropriate directory into the \bin\Debug directory the csharp project is built into.
This should be possible, since the IDE knows everything there is to know about where the DLL gets built, and where the C# application gets built.
In Visual Studio 2010:
I've tried "Dependencies..." on the csharp project and adding a dependency on mycppproject, but that has no effect.
I've tried "Add Reference..." on the csharp project and adding a reference to the cpp project, but I get a warning message 'The Target Framework version for the project "mycppproject" is higher than the current project Target Framework version. Would you like to add this reference to your project anyway?' (Yes/No/Cancel).
Clicking "Yes" produces the error message "A reference to mycppproject" could not be added."
You cannot add a reference to an unmanaged DLL.
Instead, you should make a post-build task to copy the file.
Alternatively, you can add a link to the unmanaged DLL as a file in the C# project, and set Build Action to None and Copy to Output Directory to Copy If Newer.
Visual Studio doesn't support referencing an unmanaged C++ project from a managed C# one, but MSBuild supports referencing any project from any other project.
You can manually add a reference to your project by editing the .csproj file by hand. In the file, find your existing set of ProjectReference elements (or add a new ItemGroup if you don't have one) and add the following reference:
<ProjectReference Include="..\mycpproject.csproj">
<Project>{b402782f-de0a-41fa-b364-60612a786fb2}</Project>
<Name>mycppproject</Name>
<ReferenceOutputAssembly>false</ReferenceOutputAssembly>
<OutputItemType>Content</OutputItemType>
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</ProjectReference>
When you perform the build, the reference will cause MSBuild to build the referenced project first. The ReferenceOutputAssembly value tells MSBuild not to copy the output assembly of the build (since the C++ project does not produce one), but the OutputItemType and CopyToOutputDirectory values instruct it to copy the output content to the referencing project's output folder.
You will be able to see the reference in Visual Studio, but you can't do much with it there.
This answer is based on a similar problem solved by Kirill Osenkov on his MSDN blog: https://blogs.msdn.microsoft.com/kirillosenkov/2015/04/04/how-to-have-a-project-reference-without-referencing-the-actual-binary/
I would follow Slaks' second answer...
[...] you can add a link to the unmanaged DLL as a file in the C# project, and set Build Action to None and Copy to Output Directory to Copy If Newer.
... followed by my comment, to differentiate between Debug and Release builds (even if is a little bit "hackish", since it requires you to manually edit the C# project file)
open your C# project's csproj file with a text editor and search for all "YourNativeCppProject.dll" occurrences (without the ".dll" subfix, so if you added pdb files as a link too, you'll find more than one occurrence), and change the Include path using macros, for example: Include="$(SolutionDir)$(ConfigurationName)\YourNativeCppProject.dll
PS: if you look at the properties (F4), VS shows you the Debug's path even if you switch to the Release configuration, but if you compile, you'll see that the dll copied to output is the release version*
Add Rederences only works for .NET assemblies, .net projects in the same solution or for COM components ( for which a manager wrapper will be created anyway... ).
the fact that in your C# code you access the C++ dll with DLLImport does not mean that Visual Studio will know from where to where the external dll should be copied.
Imagine that DLLImport is a runtime option, the path you puth in there is used at runtime to look for the dll, so you have to deploy the c++ dll yourself and make it available for the .net application, usually in the same bin folder.