I am getting the following exception while referencing a .Net standard 2.0 project from WPF application developed using .Net framework 4.6.1 project
Could not load file or assembly 'Microsoft.EntityFrameworkCore, Version=2.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The system cannot find the file specified.'
Any suggestions?
As of today (using VisualStudio 2017 15.8.4) this still seems to be a common problem:
Transitive dependencies are not correctly handled with the package management format which uses the packages.config file to reference dependencies.
The problem is that VisualStudio 2017 still uses this old package management format by default when you create a new WPF desktop project.
Solution
The solution is to migrate the project references from packages.config file to the new PackageReference node in the .csproj project file.
VisualStudio can do this migration automatically for you. The migration is documented here:
https://learn.microsoft.com/en-us/nuget/reference/migrate-packages-config-to-package-reference
Please note that there is a known issue:
The Migrate packages.config to PackageReference... option is not available in the right-click context menu until NuGetwas initialized.
Another option if your project does not have any package references at all is to change the setting of RestoreProjectStyle to PackageReference in your .csproj file.
https://learn.microsoft.com/en-us/nuget/consume-packages/package-references-in-project-files#using-packagereference-for-a-project-with-no-packagereferences
I hope this helps.
Add reference to Microsoft.EntityFrameworkCore package in your WPF project.
Related
Attempting to create nuget package to upload to our own nuget sever, and would like to eliminate the manual process of creating and editing the nugspec file. Everything I've read, says the setting can be pulled from the project file (if using package reference). And that the settings exist on the Package tab of the project properties window. But that tab is not there.
Using vs 2019, .NetFramework 4.7.2, project is a library, and has been migrated to package reference.
I took an existing project, right clicked the references, and used the migrate option. Package tab is non-existent
I also set the nuget package manager to default to packageReference, and create a new class library.
Package tab also non-existent
The required package (when using non-SDK Style with package reference) nuget.build.tasks.pack has bee added to the references of both projects mentions
Any help would be appreciated
The package tab is only available for SDK style projects. Non-SDK style projects use a different project system in Visual Studio, which doesn't contain that project properties tab. The new project system (on github, the old one is closed source) was initially made to look the same as the old project system, but slowly they're diverging. The Reference/Dependencies node in Solution Explorer is one obvious example, as is the Package tab in the project properties window.
To create the MSBuild properties used by pack, you'll need to manually edit the project file as XML. Within Visual Studio, you need to right click the project in Solution Explorer, select "unload project", now when you single click the project, or right click and select edit, you'll see the project XML. Once done, right click the project again and select reload project. Alternatively, edit it with a text or XML editor outside of Visual Studio, and Visual Studio will detect the change and prompt you to reload the project when you alt-tab back.
My suggestion, however, is to convert your non-SDK style project to an SDK style project. "Standard" class library projects work fine, and I'm not aware of any disadvantages (unless some developers on your team are using Visual Studio 2015 or earlier still), given the non-SDK style project is already using PackageReference. Some other project types might have limited Visual Studio experiences when targeting .NET Framework in an SDK style project. Other project types might not be compatible with SDK style projects at all. However, most people creating NuGet packages are doing so with standard class library projects, which shouldn't have any problems.
There is a "unsupported" tool try-convert to convert non-SDK style projects to SDK style. Personally, I just delete the csproj, create an empty directory, run dotnet new classlib on the console, move the csproj to my existing project's directory, rename the project file, and delete that temporary/empty directory. If you have anything other than .cs files in your project that need explicit entries in the csproj, hand edit the csproj if you're comfortable with msbuild, otherwise load the project in Visual Studio and use the Solution Explorer and Properties windows.
Some people believe that SDK style projects are only for .NET Core or .NET Standard. That's not true, but unfortunately the Visual Studio new project templates give that impression. You will need to create the class library project targeting .NET 5, .NET Standard, or .NET Core. But once the csproj is created, edit the csproj (with SDK style projects it's no longer necessary to unload the project) and change <TargetFramework>net5.0</TargetFramework> to <TargetFramework>net472</TargetFramework>. Another advantage of SDK style projects is it's easy to multi-target, a useful technique to slowly modernize your projects to newer runtimes. Add an s to the XML element name to make it plural, and add extra target frameworks as a semi-colon delimited list <TargetFrameworks>net472;net5.0</TargetFrameworks>. When changing between TargetFramework and TargetFrameworks, Visual Studio should prompt you to reload the project, but I found that it still has some issues. So I suggest closing the solution and opening it again, then everything should work great.
When I create a clickonce deploy of a wpf application many microsft dll's are missing in the deployment.
f.e. system.dll, system.data.dll, system.reactive.core.dll, system.xaml.dll, ...
Any suggestions ?
Since you still need to install the .NET Framework on the computer on which you want to install the ClickOnce application, it doesn't make much sense to include these assemblies in the deployment. They should be available in the GAC anyway.
You can include any other assemblies - including the system.reactive.* ones - by including them under Project->Properties->Publish->Application Files... in Visual Studio before you publish.
If you set the Copy Local property of these assembluies to True in the Solution Explorer, they should be included by default.
Note that if these assemblies are referenced from another project than the one you publish, you should copy the references to the WPF application project that you publish. If they are part of a NuGet package you should also add that NuGet package to the project being published.
Adding MVVM Light reference to a WPF projects adds a large number of system assemblies to the list of dependencies in the accompanying MSI Setup project. These assemblies (50+ in number) are then copied to the application folder when the app is installed. Why is it so? Why can't it reference it from GAC directly?
Note: Copy Local option is set to True for MVVMLight.dll. I obviously can't set it to False.
Reproducing it is extremely simple. I'm using VS2015 Community.
Create a new WPF Application project.
Add NuGet reference to MVVM Light (or the Lib-only version; doesn't matter).
Add an MSI Setup project to the solution (must have the extension installed).
Add Primary Project Output of WPF application to the setup project.
There you go. A long list of System.X.Y will be added to the list. If you build and install the setup project, you'll see all these DLLs in Program Files folder.
Why? And how to fix it?
Update
The problem does not appear if WPF application targets .NET Framework 4.0 and you add NuGet reference AFTER that. But if you target .NET 4.5, 4.5.1 or 4.6, the long list of dependencies appears again. Think MVVM Light (or NuGet) is having trouble finding the correct package sub-folder.
I don't know why it happens but I can offer a workaround. Just open the project's Detected Dependencies folder, select all of the System dlls, right-click and select Exclude.
Overly agressive dependency scanning is one of the many reasons I don't use Visual Studio Deployment Projects. Instead I use WiX / IsWiX. Both open source and the later written by myself.
For more information see:
http://www.github.com/iswix-llc/iswix-tutorials
I have created a VS2013 solution that contains multiple projects. One of those projects is a portable class library targeting .NET 4.5+, Silverlight 5, Windows Store 8+ and Windows Phone 8 and this project contains a reference to an OData service in an accompanying web application.
The portable class library references Microsoft.Data.Services.Client.Portable (among others), added via nuget (WCF Data Services Client).
I have then added the portable class library to a WPF (.NET 4.5) application, a Windows Store application and a Windows Phone application and written some very basic test code to access the service. This works fine in Windows Store and Windows Phone.
The WPF application however will not compile. The errors are...
The type 'System.Data.Services.Client.DataServiceContext' is defined
in an assembly that is not referenced. You must add a reference to
assembly 'Microsoft.Data.Services.Client.Portable, Version=5.6.0.0,
Culture=neutral, PublicKeyToken=31bf3856ad364e35'.
The type 'System.Data.Services.Client.DataServiceQuery`1' is defined in an
assembly that is not referenced. You must add a reference to assembly
'Microsoft.Data.Services.Client.Portable, Version=5.6.0.0,
Culture=neutral, PublicKeyToken=31bf3856ad364e35'.
The thing is, I also added the WCF Data Services Client to the WPF application via nuget, but it does not add a reference to the portable library (packages\Microsoft.Data.Services.Client.5.6.0\lib\portable-net45+sl5+wp8+win8\Microsoft.Data.Services.Client.Portable.dll), instead adding a reference to the full framework 4.0 version (packages\Microsoft.Data.Services.Client.5.6.0\lib\net40\Microsoft.Data.Services.Client.dll) - which in turn is causing the error I am seeing.
Is there something I am doing wrong here or is this an error in the installation package? Note that if I delete the offending reference and add the alternative reference manually then all is well so though I have a work-around I would still like to know if I am the cause of the error.
Looking at the NuGet source code this behaviour seems to be by design.
The WCF Data Services Client contains assemblies for the following frameworks:
.NET Framework, v4.0
.NET Portable, net45, sl5, wp8, win8
Silverlight, v4.0
Installing this NuGet package into a project that targets .NET 4.5 will result in the .NET 4.0 assembly from the NuGet package being referenced. NuGet considers the more specific .NET framework to be a better match for your WPF project which targets .NET 4.5.
There is a comment in the NuGet source code about this when it looks for the best matching assembly in the NuGet package.
// Let's say a package has two framework folders: 'net40' and 'portable-net45+wp8'.
// The package is installed into a net45 project. We want to pick the 'net40' folder, even though
// the 'net45' in portable folder has a matching version with the project's framework.
I've got this error that I just can't figure out.
I'm using VS 2012 (VS11) on Windows 8 with .net4.5 and I get this error when compiling a project that worked with VS 2010 and .net4.0.
This is the full error:
The type System.Windows.Input.ICommand exists in both 'c:\Program
Files (x86)\Reference
Assemblies\Microsoft\Framework.NETFramework\v4.0\PresentationCore.dll'
and 'c:\Windows\Microsoft.NET\Framework\v4.0.30319\System.dll'
If anybody could provide some insight on what is causing it and/or how to fix it I'd be grateful.
Thanks.
c:\Windows\Microsoft.NET\Framework\v4.0.30319\System.dll
The message is accurate, ICommand indeed exists in both assemblies for .NET 4.5. The problem is your reference to System.dll, your project is using the wrong one. The assemblies in the Microsoft.NET directory are no longer suitable to act as reference assemblies, like they were in versions of .NET prior to .NET 4.0. They should no longer be there but unfortunately are required to get C++/CLI projects built.
Your reference to PresentationCore.dll is correct, it uses the c:\program files\reference assembly subdirectory. The proper home for reference assemblies in .NET 4.0 and up. These assemblies are special, they contain only metadata and are not a copy of the runtime assemblies.
You'll need to fix your project. System.dll is probably not the only assembly that has this problem. Open the References node of your project and verify them one by one. Remove bad ones that point to Microsoft.NET and replace them with good ones by using Project + Add Reference. Best to just replace them all to be sure.
I had a similar problem with fxcopcmd V12.
I was able to solve it by explicitly adding
/reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\WindowsBase.dll"
See: FxCop engine exception on WPF assembly
Take a look at this similar post, How can I resolve this? The unit type exists in two dll files, it suggests that you are referencing two assemblies with the same type, so you would need to give the type you want to use the fully quantified name.
We had the same problem with our libraries after moving to a new build server.
The solution was to specify the path of the .net framework to build against:
/p:FrameworkPathOverride="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0"
If the .net 4.0 framework (Multi-Targeting Pack) is not installed on the build server (as it was with us), you can just copy the "v4.0" folder with all its assemblies to the build server ;)