I have added .Net Standard Library 2.0 and I have installed EntityFramework 6.4.0 via NuGet Package manager, But unable to inherit DbContext in my class because System.Data.Entity is not available. What should I do to use DbContext?
As #magicandre1981 said, you need to upgrade to .NET Standard 2.1.
I hate all these hidden version incompatibilities! We had EntityFramework 6.2 running in a .NET Standard 2.0 project. Updating EF produced no version incompatibility warnings, even though if you look closely from EF 6.3+ it requires .NET Standard 2.1.
Edit: And the calling project is Framework 4.8, which does NOT support .NET Standard 2.1. So it's back to EF 6.2 and .NET Standard 2.0 for me.
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I have created .net standard library project and I have created nuget package for this library, Now I need to install this package in both application .Net Core and .Net Framework4.5. Working fine in .Net Core but while installing .Net framework project it was showing below exception.
You are trying to install this package into a project that targets '.NETFramework,Version=v4.5.2', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
Please let me know the right approach to resolve this.
The library that you have created targets .NET Standard 2.0, as stated in your tags. .NET Framework 4.5.2 does only implement .NET Standard up to version 1.2, that is why the assemblies are not compatible.
You should change your library to a .NET Standard version that is implemented by both .NET Core and .NET Framework or upgrade your .NET Framework version accordingly.
You can find the version mappings here, credits to #Matt Ward for providing the source.
Is it possible to use Entity Framework 6.3.0 in a .NET Standard 2.0 class library?
In Dependencies -> Packages I have a reference to Entity Framework 6.3.0
And I have code like this:
using System.Data.Entity;
public partial class AlertContext : DbContext
But I get the following errors:
The type or namespace name 'Entity' does not exist in the namespace
'System.Data' (are you missing an assembly reference?)
The type or namespace name 'DbContext' could not be found (are you
missing a using directive or an assembly reference?)
6.3.0 was the first version of Entity Framework 6 to target .NET Standard; it targets .NET Standard 2.1 along with .NET 4.0 and .NET 4.5, as can be seen in its Nuget listing. 6.2.0 only targeted .NET.
Note that .NET Standard 2.0 is still not a valid target.
Depending on your scenario, you might be able to get away with multi-targeting your library to .NET (in my example below, .NET 4.7.2) and .NET Standard 2.1:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFrameworks>net472;netstandard2.1</TargetFrameworks>
</PropertyGroup>
</Project>
Whether this is viable depends on 2 factors:
Your other references. The combination I offer above will be fine in most cases as .NET 4.7.2 and .NET Standard 2.1 can reference .NET Standard 2.0 packages, which covers most but by no means all modern packages.
The frameworks that you wish to consume your library from. The .NET target means, of course, that the library can be consumed by .NET Framework projects of the same .NET version or higher. The .NET Standard 2.1 target allows the library to be consumed by projects targeting .NET Standard 2.1, .NET Core 3.0, Mono 6.4, and higher, plus the latest versions of Xamarin. The notable omission is versions of .NET Core prior to 3.0. EF6 is not available to .NET Core 1 or 2. See the .NET Standard .NET implementation support table for the full list.
* I have used .NET 4.7.2 for my illustration because whilst .NET 4.6.1 officially supports .NET Standard 2.0, Microsoft recommend using 4.7.2 or higher. See my answer here for more information.
I found two alternatives:
downgrade EF to a lower version (6.2) or
Nuget install Microsoft.EntityFrameworkCore and use the following :
using Microsoft.EntityFrameworkCore;
public partial class AlertContext : DbContext
It seems that PostSharp.Patterns.Diagnostics.dll is not available for .NET 3.5.
I'm unable to use logging on .NET 3.5. Switching to .NET 4.0 works fine; however I need to target .NET 3.5.
When on .NET 3.5 the logging smart tag is also not available.
Is this the expected behavior?
PostSharp Pattern Libraries are not supported on .NET 3.5.
On the other hand PostSharp Aspect Framework (core of PostSharp) and PostSharp Architecture Framework are supported.
I am rather confused about the behaviour of Nuget Package manager and Entity Framework. As far as I have been seraching, Entity Framework supports only version 3.5 in .NET 3.5 (which was shipped with the .NET SP1). However, when I run Nuget Package it offered me to install EF 5 and today (upgrade to) EF 6.0.1. I am using Visual Studio 2010 and the project is a class library with target framework .NET 3.5.
My questions:
a) Can you use EF 5 or 6 with .NET 3.5? - My answer is no as well as some other answer in here.
b) How is it possible that Nuget offers me to download these versions?
c) I downloaded EF 5 with Nuget and it worked. How is that possible? (Even on EF website they say it is only for .NET 4.0 and higher)
We, the Entity Framework team, decided not to fix this issue (See Work Item 1341)
Only the version of System.Data.Entity.dll that ships with .NET Framework 3.5 will work with projects that target .NET Framework 3.5.
I'm trying to use Autofac with my current application but I'm using the .NET 3.5 and the NuGet package only works with the .NET 4.5.
What is the best (or latest) release that I can use with ASP.NET and .NET 3.5?
If my eyes work correctly, this list shows that Autofac 2.6.3.862 is the latest stable release for .NET 3.5.