I was trying to create a common library for using HttpClient to consume an API. I was planning to make it in .net standard so as to share it with my xamarin.forms project right now and any future ones. However the highest version of .net standard I managed to use was 1.0. HttpClient needs standard2.0. I have included the latest version of .netstandard nuget into my xamarin.forms.
I have noticed that xamarin.forms runs in net4.5. According to the documentations the max I can go with this is standard1.1. Is there any work around around these to a .net standard common project or is my only option to make a .net framework project/xamarin portable library?
I used to be in the same situation and I managed to pull through this. First I tried to upgrade my current PCL project to .netStandard, but it was always failing, so I decided to create a new Project A Class Library (.NETStandard), moved all my files to the new project and re-install all nuget packages.
New project configuration:
Target Framwork: .NET Standard 2.0
Output type: Class Library
Make sure you're using Microsoft Visual Studio > version 15.3
Hope it helps.
I did manage to get HttpClient working in .net standard after manually importing the class. It needed an additional reference which is why it threw an error when I downgraded from .netcore.
This seems to work sometimes and throws reference errors other times. These errors go when I close and re-open visual studios.
Related
Reproduction of problem here: https://github.com/Arrow7000/SqlProviderTest
I'm fairly new to the .NET world so am having trouble wrapping my head around exactly what the problem is.
I've tried to use the SQL type provider directly in an F# .NET Core project, but had a bunch of problems getting it to work. From what I can tell that's due to incompatibilities between .net core and type providers.
So what I am trying instead is to have the SQL type provider code encapsulated in a .NET Standard project that I can reference from my main Core project.
I've managed to reproduce the problem in a minimal GitHub repo located here which demonstrates both that
the type provider is working in Visual Studio 2019 with IntelliSense, but
despite this I still get a build error when I try to start the Main project
The build error is
Unable to find the file 'C:\projects\SqlProviderTest\SQLStuff\bin\Debug\netstandard2.0\SQLStuff.dll' in any of
C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.netcore.app\2.2.0\ref\netcoreapp2.2
C:\projects\SqlProviderTest\Main
C:\Users\Aron\.nuget\packages\fsharp.core\4.6.2\lib\netstandard1.6
Why isn't the project reference simply working as expected? I've tried adding <Private>True</Private> to the project reference but that didn't make any difference
P.S. in case it matters, I'm developing on Windows but the app gets deployed on a Docker container.
I'm trying to add a full framework class library as a project reference to asp.net core 2.0 MVC project and getting the below error.
Project XYZ is not compatible with netcoreapp2.0 (.NETCoreApp,Version=v2.0).
Project XYZ supports: net462 (.NETFramework,Version=v4.6.2)
I have updated to the most recent version of Visual studio i.e, 15.3.5.
Is it even possible to reference 4.6.2 libraries in core 2.0 projects?
The first thing that you can try is to compile the library you want to consume as netstandard2.0.
Theoretically (according to the .net standard documentation), this will make it compatible with projects using net461 and later as well as netcoreapp2.0 and later.
In practice, sometimes you will end up with a problem with one of your dependencies that don't provide the same library version across different compilation targets.
In such cases you may simply need to add the .net core 2.0 as a target framework for the XYZ library.
The xml tag listing the targets is <TargetFrameworks> in the XYZ.csproj file and is not handled by the Gui of the project's properties.
So I would give a try at editing the XYZ.csproj by hand and add or replace what's listed as <TargetFrameworks> with netcoreapp2.0.
If you are adding it as additional target you need to separate them with ';' as in
<TargetFrameworks>net462;netstandard2.0;netcoreapp2.0</TargetFrameworks>
More details about this in this Microsoft doc.
Please keep in mind that this will trigger multiple compilations and will slow your build consequently...
It should be. Microsoft announced a ".NET Framework Compatibility Mode" with the release of .NET Standard 2.0. However, they didn't go into great detail about how it works exactly, or what to troubleshoot if it doesn't. Additionally, they only specific talk about it in relationship to Nuget packages, so it's possible there's some role Nuget is playing in the process, as well. Unfortunately, I've been unable to find any additional information about this feature outside of the announcement post.
That said, Microsoft's explicit recommendation is to not rely on the fact that your .NET Framework library may just happen to work in .NET Core; instead, you should be actively porting .NET Framework libraries you control to .NET Standard. I'd say you're likely going to spend more time trying to figure out why it doesn't "just work" than you would porting your code, so that it will definitely work, and be future-proof to boot.
The following solution worked for me.
Deleted bin and obj folders from all the projects in the solution, rebuild and if it still doesn't work try changing browser from debug options. for eg. If you already have chrome as default browser in Visual studio, switch to Edge or Firefox.
I'm working in Visual Studio 2015 Update 3 and .NET Core 1.0. I have a Web API project which is of type .NETCoreApp v1.0. When I add a .NET Core class library, it is of type .NETStandard v1.6. I can add this library to the Web API project as a reference, but it is not recognised when I try to add using statements.
If I create another project of type .NETCoreApp, I can reference it and use the classes without a problem.
How do I make use of a .NET Core class library from my .NET Core App?
Edit/Update:
This appears only to be an editor/Intellisense issue, because despite the editor warnings, the .NETCoreApp does build and run, calling into the class library.
I am running Resharper, which I see is blamed for similar problems with other types of projects: I have checked that I have the latest version and have cleared the Resharper cache and restarted VS2105.
This is a Resharper issue. At this time Resharper (v2016.1.2) does not support .NET Core 1.0.
There are 2 possible solutions:
Uninstall Resharper, and the Visual Studio native intellisense works.
Install the Resharper 2016.2 EAP (Early Access Program) version. I've done this and it's working. Obviously it comes with the caveats of any EAP/beta product.
Here is a link to the Jetbrains forum post where I was told .NET Core 1 was not yet supported and pointed to the EAP version.
Once you've built a library that targets netstandard1.X, you can either:
Produce a NuGet package with dotnet pack and host it locally or on NuGet. Then, install it in your netcoreapp project as any other dependency.
If your library and application are part of the same solution, make a local reference:
project.json
"dependencies":{
"MyLibrary.Core": {
"version": "1.0.0",
"target": "project"
}
}
target: project tells dotnet to look in the current solution for the dependency, instead of using your NuGet feeds. Again, this only works if you are developing the library and application in the same solution.
I am trying to add search to an Asp.Net 5 project. The search uses the Bing Search API.
As per the instructions in the "Bing Search API – Quick Start and Code Samples" I have downloaded a file called "BingSearchContainer.cs". This file has references to System.Data.Services.Client. The file is too big to put here but can be downloaded at https://datamarket.azure.com/dataset/explore/getproxy/5ba839f1-12ce-4cce-bf57-a49d98d29a44.
I added references to System.Data.Services and System.Data.Services.Client as they were not included in the generic Asp.Net 5 (RC1) template I have used (in Visual Studio 2015) to create the site.
Although this removes the errors in the files themselves, the errors are still present in the error list and the project won't build or run.
If I hover over the using statement for System.Data.Services.Client at the top of the BingSearchContainer file it says ....DNX Core5.- Not Available.
Does anyone know how I can solve this?
You need to be aware of the platforms you're targeting. .NET Core is a new runtime, and there are no built-in libraries. Everything must be added (generally as a NuGet package), even things that were previously available from the Standard Libraries.
Check and see if the library you want is available on NuGet. If not, you'll need to find some sort of workaround or stop targeting .NET Core and just focus on the full .NET Framework.
Some workarounds
Locate a different package that does what you want and is available for both .NET Core and the full .NET Framework
Use System.Data.Services.Client on full .NET Framework and an alternative framework for .NET Core, and use compiler directives to target specific blocks of code at specific versions of the framework
Location the source for System.Data.Services.Client and try porting it to .NET Core. You should probably double check with Microsoft about this to see if they have plans to move it over already, as well as to see if there's anyone else that might help you with it
Just compile your project for .NET Framework, and don't compile for .NET Core
I have a Web API that has version 5.1.2 of the Microsoft.AspNet.WebApi.Client package installed.
I am trying to access the API from an ASP.NET MVC application, which also has the same version of the package installed.
However, in the Global.asax of the Web API project, on the line below, I get the following exception:
WebApiConfig.Register(GlobalConfiguration.Configuration);
Attempt by method 'System.Web.Http.HttpConfiguration..ctor(System.Web.Http.HttpRouteCollection)' to access method 'System.Web.Http.HttpConfiguration.DefaultFormatters()' failed.
I found that this error occurs when you have multiple projects pointing to different .net versions.
For example if you have a Web API project targeting .net 4.5 and a unit test project targeting .net 4.5.3 it seems that default settings mean nuget may silently update the .net 4.5 project references to incompatible versions one day when you open visual studio and cause your Web API project to fail with the recondite 'Attempt by method 'HttpConfiguration..ctor(HttpRouteCollection)' to access method 'HttpConfiguration.DefaultFormatters()' failed' error.
To avoid the error drop the higher .net version back on the new project to match the Web API project - for this example right click the unit test project, click properties, then change the target framework to .net framework 4.5.
In my case it was a discrepancy between versions of Microsoft.AspNet.WebApi.Client and Microsoft.AspNet.WebApi.Core, I tried updating both to the same version and it worked.
In my case, the issue was solved when I installed the Microsoft.AspNet.WebApi.Core as well. So three libraries should present and be in harmony (uninstall / install) Microsoft.AspNet.WebApi.Client, Microsoft.AspNet.WebApi.Core and Newtonsoft.json
same for the above answers in my case also it is working good after updating or reinstalling packages
Microsoft.AspNet.WebApi.Client
Microsoft.AspNet.WebApi.Core