I am working on creating a sample Nuget package to test out the process of creating an internal Nuget package for use in another project of mine. My end goal is to create a simple Nuget package, which can be installed onto another simple C# project, and tested out.
I have been following the Microsoft tutorial to create & publish a package using VS:
https://learn.microsoft.com/en-us/nuget/quickstart/create-and-publish-a-package-using-visual-studio-net-framework
I successfully created & published my package on nuget.org, called MyNugetPackage, and attempted to install it onto my other C# project called TestingMyNugetPackage. I received an error in the NuGet package console stating:
Package does not support any target framework
This error makes sense, because I had read about supporting multiple .NET versions and specifying the version under the lib folder, and I definitely did not do that when creating my package:
https://learn.microsoft.com/en-us/nuget/create-packages/supporting-multiple-target-frameworks
This idea of lib folder makes sense to me and I think I understand how to add my target .NET version to it. However, I cannot find this folder anywhere! It's not anywhere in the C# project directory. I assume I may need to create it on my own, but I'm not sure where to put it.
Many tutorials and SO questions I have read about this topic talk about how to use the lib folder, but no one ever says where it is. I'm a complete beginner to this and I know I am missing something obvious here, but I'm not sure what it is.
Edit: I did try to change my .nupkg file to a .zip file and extracting the contents in attempt to view the lib folder. This did work in extracting the contents, but I did not see any lib folder after expanding entire project tree and searching for lib.
Here is a quick layout of my C# solution tree:
Solution titled MyNugetPackage with a MyNugetPackage.sln file, a MyNugetPackage.csproj file, and a simple class Logger.cs that just has a public void Print(string text) { Console.WriteLine(text); } method:
MyNugetPackage
MyNugetPackage.csproj.1.0.0.nupkg
MyNugetPackage.nuspec
MyNugetPackage.sln
MyNugetPackage (folder)
bin (folder)
Debug (folder) -> .dll, .pdb
Release (folder) -> .dll, .pdb
obj (folder)
Debug (folder)
Release (folder)
Properties (folder)
AssemblyInfo.cs
Logger.cs
MyNugetPackage.csproj
Could someone direct me where I need to place my lib folder, so that I can add my supported .NET 4.7 framework reference, and successfully install my package?
A NuGet package (.nupkg) is just a zip file. If you are trying to view the contents of this file, open it like a zip file (using 7zip or something). Alternatively change the extension to zip. In the package you will find the "lib" folder as well as the .nuspec, and package folder (among other contents). But this is the resulting package that is built when you Pack your project, changes here would have no affect on your code.
If you're just trying to target one or more frameworks. In VS, edit your project file (.csproj). This file is an XML with a PropertyGroup that contains either a "TargetFramework" OR a "TargetFrameworks" element. To target a single framework add a TargetFramework element, to target multiple use the TragetFrameworks instead.
To target a single .Net framework:
<PropertyGroup>
<TargetFramework>net472</TargetFramework>
</PropertyGroup>
Alternatively, you can target multiple frameworks.
<PropertyGroup>
<TargetFrameworks>net472; netcoreapp3.0; netcoreapp2.1</TargetFrameworks>
</PropertyGroup>
This would target .Net 4.7.2, .Net Core 3.0, and .Net Core 2.1
Related
I have two class libraries in a single solution (.NET Core). One of them (cl1) is a main library and it depends on another library (cl2). I have added a .nuspec file with the required metadata only (no dependencies, no files) for the cl1 project in the project folder (same location of .csproj file) and I have set GeneratePackageOnBuild propery to true.
Whenever I am building the class library (cl1), the .nupkg is created automatically in the debug/release folder.
When I check the generated .nupkg file, I am see two strange things:
The generated .nuspec file is different than what I have added in the project folder
cl2 is mentioned as a dependency in the newely generated .nuspec file, but the DLL for cl2 is not included in the lib folder of the .nupkg. So, whenever I consume this package in another solution, I am getting the error No packages exist with this id in source(s) for the cl2.
I have surfed in internet, but was not able to find a proper solution for the above error.
And I have added a .nuspec file [...] in the project folder(same location of .csproj file)
You have to specify the path to your own NuSpec file in the .csproj using the NuspecFile tag, otherwise it will be ignored and the package will be created with the metadata from the .csproj file instead, see reference. You need to use either a relative or an absolute path to the file, for example:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<NuspecFile>cl1.nuspec</NuspecFile>
</PropertyGroup>
</Project>
The generated .nuspec file is different than what I have added in the project folder
As already stated, your NuSpec file is probably not included. However, even if it is, there can be differences, because some information, e.g. source file locations are unnecessary and the target locations are in most cases given by the internal package file structure itself, so it is not there because it is redundant.
cl2 is mentioned as a dependency in the newely generated .nuspec file, but the dll for the cl2 is not included in the lib folder of the .nupkg. So, whenever I consume this nupkg in other solution, I am getting error " No packages exist with this id in source(s)" for the cl2.
Dependencies are meant for packages. So when NuGet restores the package it searches for other packages that this package depends on, here cl2, but there is none, hence the error. When packing a project, referenced projects are not included in the package. That is an open issue and there are workarounds that you can try.
The most reliable, but inconvenient solutions are to avoid the issue at all.
Only use a single project, everything will be included in the package
Pack each project on its own and use the generated package instead of the referenced project
Context
I have a Managed C++/CLR library which is built using CMake 3.17, and packaged into a NuGet package using CPack. The resulting nupkg file cannot be imported into a C# project, as the Package Manager issues the following error: "[snip] the package does not contain any assembly references or content files that are compatible with [.NETFramework,Version=v4.5.2]". However, adding a reference to either the project when added to the solution, or the corresponding library file generated by the build, works as intended.
C++/CLR Details
The code itself is very basic and produces a valid library which can be referenced from another project, when manually adding a reference via Visual Studio 2017 -> Add Reference (either the project or the corresponding library can be added this way and it works all the same).
The code consists of the class itself, and AssemblyInfo.cpp provides attributes which describe the metadata and version information only. The dependencies include only System, System::Runtime::InteropServices, and a raft of pre-built native libraries.
I have not added a .nuspec file, nor a nuget.config file, the latter which I believe is generated by the CPack NuGet generator when the package is built.
CMake / CPack Details
CPack NuGet support is relatively new, and I have been unsuccessful in finding a working example, but I have managed to successfully generate a nupkg file. Firstly CMake is instructed to build a Managed C++ library with the included source files, and the following properties set on the corresponding target ManagedLibrary:
set_target_properties (ManagedLibrary PROPERTIES DOTNET_TARGET_FRAMEWORK_VERSION "v4.5.2")
set_target_properties (ManagedLibrary PROPERTIES COMMON_LANGUAGE_RUNTIME "")
The documentation states that this will generate CLR/Mixed code and works as advertised, so I am able to successfully build against the target framework. The next step was to install the library in what I believe is the correct location:
install (TARGET ManagedLibrary DESTINATION . COMPONENT MixedCLR)
And supporting (native C++) libraries are installed similarly:
install (FILES [various..] DESTINATION . COMPONENT MixedCLR)
I also set CPACK_GENERATOR to 'NuGet', and then run the PACKAGE step from the CLI using cmake --build . --target PACKAGE which successfully produces the nupkg file.
Question
How does NuGet know what libraries to add a reference to?
Is a nuspec file required? If so, what must minimally be included in it, and how do I include it in the target CMakeLists.txt?
Is it acceptable to put the managed library, along with supporting native libraries, in the root of the package? If not, where should they go?
Are any other files generally included in a nupkg file?
Finally, if anyone knows anything about packaging and multi-targeting in C++/CLR to support different framework versions / architectures / build configurations, any notes on that would be highly appreciated.
How does NuGet know what libraries to add a reference to?
Primarily NuGet infers the libraries to reference from the package structure. Managed assemblies must be put in a directory which is libs/<TFWM> where TFWM is the Target Framework Moniker (eg: .NET Framework 4.5.2 => net452).
Is a nuspec file required? If so, what must minimally be included in it, and how do I include it in the target CMakeLists.txt?
The nuspec file is automatically generated by CPack at package generation time. The generated file is saved to the output directory, and will preserve the directory structure specified by the install command.
Is it acceptable to put the managed library, along with supporting native libraries, in the root of the package? If not, where should
they go?
As already discussed, the managed libraries go in libs/blah. Native libraries, on the other hand, go in runtimes/<RID>/native where RID is the Runtime ID. In my case I wanted to target Windows 64-bit, so the Runtime ID is win-x64.
Are any other files generally included in a nupkg file?
I bundle the PDB for convenience, but I didn't need to specify any other files or properties.
Finally, if anyone knows anything about packaging and multi-targeting
in C++/CLR to support different framework versions / architectures /
build configurations, any notes on that would be highly appreciated.
If targeting multiple framework versions it's simply a case of creating and installing multiple targets into the respective folders, there's nothing more complex to deal with.
Finally, my finished package structure looks like the following:
libs/
net452/
ManagedLib.dll
ManagedLib.pdb
runtimes/
win-x64/
native/
NativeLib1.dll
NativeLib2.dll
...
I hope this helps someone in the future.
I have a very simple console project:
class Program
{
static void Main(string[] args)
{
var project = new Project(
"FishStory.csproj",
null,
null,
new ProjectCollection());
Console.ReadLine();
}
}
This is a .NET Core 3.0 console application, and it has Microsoft.Build (16.4.0) NuGet package referenced.
The .csproj file FishStory.csproj is found (I don't get an exception that the .csproj is missing), but I do get the following error.
Microsoft.Build.Exceptions.InvalidProjectFileException:
'The imported project
"C:\Users\vchel\source\repos\ForDave\ForDave\bin\Debug\netcoreapp3.0\Microsoft.CSharp.targets" was not found.
Confirm that the expression in the Import declaration "C:\Users\vchel\source\repos\ForDave\ForDave\bin\Debug\netcoreapp3.0\Microsoft.CSharp.targets" is correct, and that the file exists on disk. C:\Users\vchel\source\repos\ForDave\ForDave\bin\Debug\netcoreapp3.0\FishStory.csproj'
I'd expect that such a simple MSBuild test would "just work", but it seems like I'm missing something. What can I do to load this .csproj file?
I have catched the same exception while I have tried to load a project targeted to netcore31 platform.
But after that I have installed
Microsoft.Build.Utilities.Core(16.5.0)
Microsoft.Build (16.4.0)
nuget packages, there is no more the exception. The project is loaded successfully.
Maybe, it will help someone more.
It seems the NuGet package adds the necessary .dlls to use the Project object, but the various project types must have .target and .props files which are used when the Project .csproj is loaded.
To load my specific project, I had to add the following files to the output directory. I accomplished this by placing the files in my project and marking them as Copy if Newer.
I added the following files:
Microsoft.Common.targets
Microsoft.CSharp.targets
Microsoft.NETFramework.props
Microsoft.NETFramework.targets
In my case the .csproj is a MonoGame project, so I also had to add:
MonoGame.Build.Tasks.dll (not sure if I needed this or not)
MonoGame.common.props
MonoGame/v3.0/MonoGame.Content.Builder.targets
To add these files so they are copied to the output folder:
Add the file to your project (for .NET Core you just have to add the file to the directory)
Right-click on the file in the Solution Explorer and select Properties
Set the Copy to Output Directory to Copy if newer
I pulled the targets/props/.dll files from:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319
C:\Program Files (x86)\MSBuild\MonoGame\v3.0
I am guessing that other project types (such as an Android Xamarin project) may require different .targets files, which can be found here if using Visual Studio 2019 Community:
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Xamarin
Finally, I also had to manually add the NuGet Package Microsoft.Build.Utilities.Core. Not sure why that wasn't automatically added when adding Microsoft.Build
I'm trying to create a managed library and package it with Nuget. The managed library consumes another DLL written in C and makes the calls through [DllImport] P/Invoke calls. In the root of the project I have a folder structure like:
root/runtimes/win-x86/native/file.dll
root/runtimes/win-x64/native/file.dll
I am not using a .nuspec file but instead generating the Nuget package from the .csproj file from a .NET STandard 2.0 project. I'm including those files with this in the .csproj file.
<ItemGroup>
<Content Include="runtimes\**" PackagePath="runtimes" Visible="true" />
</ItemGroup>
The nuget package has the managed DLL in the lib/netstandard2.0 directory and even has the unmanaged DLL in root/runtimes/RID/native directory. The project that is consuming this nuget package installs perfectly and builds without error.
The managed DLL the consumer will interface with is trying to use that native DLL like this
[DllImport("file_name.dll")]
private static extern IntPtr CscanHOpen(string connectionString);
//...
public void Open(string connectionString, int port) {
_handle = CscanHOpen(connectionString, port);
}
I'm getting the "file cannot be found" error from the project installing the nuget package and when I look in the build directory I don't see that unmanaged DLL there. I've tried using a targets file to copy the unmanaged DLL to the output directory of the consuming project but it never shows up.
I keep looking back at this question because there are no answers, so I'm going to repeat what we discussed in the comments.
The runtimes feature of NuGet only works for projects using your package with PackageReference, not packages.config. In fact, despite being on the NuGet client team, I'm not actually sure if runtimes is an SDK-style project feature, or if it also works with traditional projects. Honestly, I expect it only works with SDK style projects, because it requires the rest of the build system to know how to use these assets.
Therefore the answer to your question is to test your package with a SDK-style project. All .NET Core apps are SDK style, but you can also edit the project and change <TargetFramework>netcoreapp2.2</TargetFramework> to `net48, or make the xml tag plural and the value a semi-colon delimited list of TFMs.
Also note that class libraries don't have a host, hence don't have a RID. Therefore you may not see the runtime dlls. You need to make sure your test project that uses the package is something that has a host & entry point, like a console app.
To support packages.config projects (and probably traditional projects using PackageReference) you will need to bundle your own props and targets file in the package. You said you tried it, but it didn't work, which unfortunately just means you were doing it wrong. NuGet has a convention on how you must name your props and targets file. If you got that right, then the way you implemented copying the files didn't work. You can use MSBuild's increased verbosity, or msbuild -bl coupled with the MSBuild structured log viewer to debug your targets file.
Using the runtimes feature is so uncommon I don't really have any experience with it and don't know how to support both traditional projects, while using the integrated runtimes support in SDK style projects. I suggest you'll need to make sure your targets have a condition to run only when it's not an SDK style project, but I don't know how you'd detect that.
I'm looking forward to setup an environment/configuration that allows me to build and deploy a custom library for multiple platforms / targets, such as build configurations and/or .NET framework versions. For this, I've laid out the following structure:
MyProject.sln
src\
File1.cs
File2.Net30.cs
MyProject.Net40.csproj
MyProject.Net30.csproj
MyProject.Net45.csproj
All project files are included in the solutions and built at once. Each project contains the source files for the framework it targets and/or all files where as different .NET versions are compiled conditionally (using compiler directives, e.g. NET35, NET34_OR_GREATER). Additionally, each project file contains the following msbuild directives:
<OutputPath>bin\$(Configuration)\$(Platform)\$(TargetFrameworkVersion)\$(TargetFrameworkIdentifier)\</OutputPath>
<BaseIntermediateOutputPath>obj\$(Configuration)\$(Platform)\$(TargetFrameworkVersion)\$(TargetFrameworkIdentifier)\</BaseIntermediateOutputPath>
<DocumentationFile>bin\$(Configuration)\$(Platform)\$(TargetFrameworkVersion)\$(TargetFrameworkIdentifier)\$(AssemblyName).xml</DocumentationFile>
This allows me to build them all at once by routing the output into different directories.
Now, that's all for building. However, I'm really stuck with deployment, especially related to NuGet. I've created a .nuspec where I include every dependency manually:
<file src="bin\Release\AnyCPU\v4.0\MyProject.dll" target="lib\net40-client\EIT.Foundation.dll" />
<file src="bin\Release\AnyCPU\v4.0\MyProject.xml" target="lib\net40-client\EIT.Foundation.xml" />
<file src="bin\Release\AnyCPU\v4.5\MyProject.dll" target="lib\net45\MyProject.dll" />
This works fine, but is really tedious. So first question: Is there any way to hook up the files automagically?
And my second problem: Sometimes my libraries have NuGet dependencies themselves. For project dependencies, a packages.config is automatically created in the same folder as the project when downloading NuGet dependencies. The packages.config not only contains the dependency or its version used in the project, but also which framework version of the dependency is required. This is a bit of a problem since every project file (for each framework target) resides in the same folder, so they would need to share the same packages.config file somehow. I'd tried relocating the project files to a different structure like this:
MyProject.sln
target\
net40\MyProject.Net40.csproj
src\
File1.cs
... however then I'm unable to preserve the folder structure in my source folder (if there's any) because the project files only allow me to include files, not folders (they are being automatically included.) Is there any way around this or is NuGet simply not suited for multi-target builds?
Whilst NuGet supports creating a NuGet package for a particular project it is targeted for single projects. The command is NuGet pack YourProject.csproj so I suspect it will not help you. Using a .nuspec file is probably the only way to get this working.
NuGet supports multiple projects in the same directory if you rename the packages.config file. Each packages.config file should be named after the project. So in your example the following should work:
packages.MyProject.Net40.config
packages.MyProject.Net30.config
packages.MyProject.Net45.config