I do have an ASP.NET MVC Core app and would like to add a Class library in my project.
I added it in my project via "Add Reference" > "Browse" > select DLL and done.
I added it on code like
using PagarMe; // works good on code
And I was able to compile and run the app. however when the user goes to a page where the lib is referenced then I got the fallowing error.:
FileNotFoundException: Could not load file or assembly 'PagarMe.Pcl, Version=2.0.6372.16631, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
What I already done.
I checked the output bin folder and the Dlls files are there.
Both DLLs are compiled with "Any CPU" configuration.
I tried PCL and non-PCL Version.
App Target framework: .NETCoreApp 1.1
Default Class Library Target Framework: .Net Framework 4.5.
Portable (PCL) Class Library Target Framework: .Net Framework 4.5 and ASP.Net Core 1.0
What can I do in order to use Class Library or PCL library into my Core App?
In .NET Core you no longer use Portable Class Libraries, but you target the correct version of the .NET Standard Library. Some PCL or Shared Classes may use some unsupported
references.
To solve this please try one of this:
1. Rebuild your Class Library to target .NET Standard. .NET Standard 1.6, for instance, is supported by both .NET Core 1.0 and .NET Framework 4.6.1.
.NET Standard can be thought of as the next generation of Portable Class Libraries (PCL). The .NET Standard improves on the experience of creating portable libraries by curating a standard BCL and establishing greater uniformity across .NET runtimes as a result. A library that targets .NET Standard is a PCL or a ".NET Standard-based PCL". Existing PCLs are "profile-based PCLs". (Taken from the documentation)
2. Target your app to .NET Framework.
You could build an ASP.NET Core application to target the full .NET Framework in stead of .NET Core only. This gives you the advantages of ASP.NET Core, without the limits of .NET Core.
ASP.NET Core != .NET Core
Related
In one of my .NET Framework projects, I introduced a new .NET Standard 2.0 project. This project has dependencies on some existing .NET Framework projects. I was wondering if this is right to do.?
The reason I added a .NETStandard project is that we have plans to move the whole repository to .NET Core / Standard. Hence I thought, the new project we add can target .NET Standard. With .NET Standard project I get the new SDK style project file, package references, etc by default.
The consuming application is still .NET Framework.
Do I have to retarget the new project to .NET Framework 4.7.2 so that the project will have the above SDK style project file and package references but targets .NET Framework 4.7.2 now. It will then be as easy as changing the target framework when we move to .NET Core?
Depends on your purpose of introducing the Standard 2.0 project. Normally, you make a Standard when you need it to be accessible both from .NET Framework and Core. In your case, your Standard project won't be operable from Core under macOS or Linux.
Yes, this can be done.
https://learn.microsoft.com/en-us/dotnet/standard/net-standard?tabs=net-standard-2-0
.NET Framework compatibility mode
Starting with .NET Standard 2.0, the .NET Framework compatibility mode was introduced. This compatibility mode allows .NET Standard projects to reference .NET Framework libraries as if they were compiled for .NET Standard. Referencing .NET Framework libraries doesn't work for all projects, such as libraries that use Windows Presentation Foundation (WPF) APIs.
This is necessary as an intermediate step for some projects, but in order to get to your final goal you will of course have to go all in on .net core which will require updating those projects not to use framework or they will crash at runtime.
Setup
Say I have a .Net Standard 2.0 class library project and I add a Nu NuGet package that is compatible with .Net Standard 2.0 to it.
I then reference that class library project from both a .Net Framework console project and a .Net Core console project.
To restate with a picture:
Question
How does each of the console applications deal with getting the right NuGet code for their type of application?
Notes
Note: I tried this using Microsoft.Extensions.DependencyInjection, and it works fine in the .Net Core 3.1 console app, but throws a "File Not Found" exception in the .Net Framework 4.7.2 console app (looking for the Dependency Injection DLL). This leads me to believe that .Net Standard 2.0 NuGets are really .Net Core NuGets...
Note to the Note: I am trying to understand what happens here, not fix the "File Not Found" issue. (That is easily fixable by referencing the Microsoft.Extensions.DependencyInjection NuGet in the .Net Framework 4.7.2 console app).
In your scenario two different package resolution startegies are used. There is the old way of managing packages with packages.config and the new way with PackageReferences. There is also the old project format of .NET Framework projects and the new SDK-style format that was introduced for .NET Core, but is also usable in .NET Framework applications.
With the old project format that is still used by most existing .NET Framework applications regardless of packages.config or PackageReference, the .NET Framework Console application is only able to access the class library, but not the assemblies of its referenced NuGet package, because it is not a direct reference but via your library, hence indirect. This is als called a transitive dependency.
In the new SDK-style project format with PackageReference, this is fundamentally different. There, transitive dependencies are possible. This means, that your .NET Framework console application can access the class library project, as well as its referenced assemblies via the NuGet package.
The SDK-style format with PackageReference is the default for .NET Core projects, so they support transitive dependencies out of the box. Only with the old project format you have to add NuGet packages manually, because it cannot access the transitive dependency through the class library. You can migrate existing .NET Framework projects to the new SDK-style format, to enable the same behavior as in .NET Core.
I have an old-style C# WPF project file. It is a .NET Framework 4.7.2 project. I want to reference a NuGet library that has builds for .NET Standard 2.0 and .NET Framework 4.5.1. An example of this would be morelinq.
As I understand it, .NET Framework 4.7.2 fully implements the .NET Standard 2.0 API. Therefore I would like my project to reference the .NET Standard 2.0 build in the NuGet package instead of the .NET Framework 4.5.1 build. The benefit of this would be that the .NET Standard 2.0 version of morelinq does not have additional dependencies, e.g. on System.ValueTuple.
However, when I add the NuGet package, it defaults to referencing the .NET Framework 4.5.1 build and hence, includes its additional dependencies.
This is only one of a few such cases. So at the moment it seems, to me at least, that I'm references many unnecessary additional dependencies that could be avoided.
(My apologies if this is a duplicate. I did try searching first.)
I've got a strange issue referencing a net standard application (FW Full 4.5.2)
I got this error targets 'netstandard2.0'. It cannot be referenced by a project that targets '.NETFramework,Version=v4.5.2'., wasn't .NET standard supposed to allow references from Core and Framework projects as well?
As stated here .NET implementation support. You need atleast .NET Framework 4.61 for referencing .NET Standard 2.0 assemblies.
I'd really like to start using .NET Core and slowly migrate applications and libraries to it. However, I can't realistically upgrade my entire code base to use .NET Core and then go through the process of testing and deploying a plethora of applications in production.
As an example, if I create a new .NET Core application and try to reference one of my .NET Framework projects I get the following:
The following projects are not supported as references: -
Foobar.NetFramework has target frameworks that are incompatible with
targets in current project Foobar.NetCore.
Foobar.NetCore: .NETCoreApp,Version=v1.0
Foobar.NetFramework: .NETFramework,Version=v4.5
Is it possible to create a new .NET Core application and reference my existing .NET Framework libraries? If so, what's the process for doing that? I've spent hours going through Microsoft's documentation and searching their issues on GitHub, but I can't find anything official on how to achieve this or what their long-term vision is for this process.
Old question, but with the release of .NetStandard 2.0 and .netcore 2.0 and vs2017.3, the game has changed.
You can use the Full .NET Framework (TFM) with .NetCore 2.0, but how?
In Visual Studio 2017.3, you can reference the Full .NET Framework (any version) directly from within a .NetCore2 project.
You can build the .NetStandard2 class library and reference your TFM. Then reference your .NetStandard2 library from your .NetCore2 project.
For example, referencing json.net net45 from .NetStandard2.
Browse to the folder and select version net45 (not netstandard1.3)
See the dependency in the image below, no yellow warning as you see.
Even if a Nuget library is not ready to be ported to .Netstandard 2, you can use any API in the library that is compliant to net461.
Quoting for the .NET Core 2/Standard 2.0 announcement with links:
.NET Core 2.0 is able to freely reference libraries that have been built for .NET Framework up to version 4.6.1
However, some libraries may fail at run time if they try to use API methods that aren't available on .NET Core
Reference: .NET Core App target .NET framework 4.5.2 on Linux
A need to use third-party .NET libraries or NuGet packages not available for .NET Core
So only in cases where the libraries or NuGet packages use technologies that aren't available in .NET Standard/.NET Core, you need to use the .NET Framework.
Reference: Choosing between .NET Core and .NET Framework for server apps
You can now reference .NET Framework libraries from .NET Standard libraries using Visual Studio 2017 15.3. This feature helps you migrate .NET Framework code to .NET Standard or .NET Core over time (start with binaries and then move to source). It is also useful in the case that the source code is no longer accessible or is lost for a .NET Framework library, enabling it to be still be used in new scenarios.
Reference: Announcing .NET Core 2.0
Yes, we are currently attempting the same thing. The trick is to make sure that you are supporting the same .NET frameworks. Inside your project.json file, make sure the framework matches the framework of the project you wish to include. For example:
"frameworks": {
"net46": { --This line here <<<<
"dependencies": {
"DomainModel": {
"target": "project"
},
"Models": {
"target": "project"
}
}
}
},
FYI: You might need to change the framework of your .NET Core or your older projects to achieve this. .NET Core can be changed just by editing the project.json file as seen above. You can so the same in .NET projects by right clicking the project and opening properties. Change the framework level there.
Once you have matched the two project frameworks then you should be able to include them. Good Luck!
We delayed migrations as long as could as it seemed daunting as first. But we got an insistent client who wanted to migrate ASAP.
So we migrated their Fintech Web App developed on .NET Framework 4.8 Web Forms to .NET 6 Razor Page. Our team scoured though hundreds of online resources & spoke to Microsoft Tech Support before we started the project. Hope the high-level walkthrough of our journey help you plan your migrations.
Our .NET Framework Website consisted of 1 .NET Web Forms project and 12 Class Libraries.
Here is how we did it.
Refactored the .NET Framework 4.8 Web Forms code
We ensured that the Web Forms code behind did not have a single line of service or business logic code. When we did find some business logic code in the web forms code behind, we refactored it, by moving it to the class libraries.
Created new .NET Standard projects
We created a new .Standard 2.0 Class library project for every .NET Framework 4.8 Class Library. If the original project was called "FintechProjectName.StockMarketClient", we named the .NET standard project "FintechProjectName.StockMarketClient.Standard".
Copied all files from .NET framework to .NET standard
We copied all the class files from .NET framework to .NET standard projects. We then removed all the .NET framework class libraries from the solution and added references to the new class libraries. All projects compiled on the 1st try itself and all our test cases too passed with minor changes.
Create new .NET 6 Web App Project
We created a new .NET 6 Web App Project. We had to entirely redo the front-end as there is no direct path for migrating Web Forms to Razor Pages. This was the only project which took us about 1 month to migrate.
Reference .NET standard class libraries in the new .NET 6 website
We copied all the .NET Standard libraries to this new solution containing the Razor Pages web site. Added the references and got it to work.
Move from .NET Standard to .NET 6 class libraries
Once the new website was up and running, with all test cases passed, we did the last step in the process which was the simplest. Created .NET 6 class library projects for each of the .NET standard libraries and named the projects appropriately. Copied all class files from .NET standard projects to their corresponding .NET 6 projects. Then we removed the .NET Standard libraries and added references to the new class libraries.
Overall project timelines were about a month and a half, most of it spend on Razor Pages implementation using the same html design.
Note:
If you are using any 3rd party library which does not have a .NET standard or .NET 5 version, then you are out of luck. You will need to find a replacement nuget package and recode your application to use this new library.
In my case with .net6 referencing framework 4.8 library ( both winforms), the trick seems to be to add the reference to the framework dll as a shared reference.