I have a C# Windows Forms project but I need to update it to the latest version of the C# language but I don't understand the documentation for updating, does anyone have an example of how to do this?
I'm using version 4.6 of Net Framework, I've tried it with 4.8 too
You can set the LangVersion property in the .csproj file to specify the C# version you'd like to use. You can set it to a specific version, or use "latest" to set it to the latest version compatible with the compiler:
<Project>
<PropertyGroup>
<LangVersion>latest</LangVersion>
</PropertyGroup>
</Project>
Be aware that only certain versions of the C# language are compatible with specific .NET versions and MSBuild Versions. The highest version of C# compatible with .NET Framework is 7.3.
You can find more information, including C# / .NET version compatibility, here:
C# language versioning
Related
I'm currently writing a project in C# 7.3 but I need to change it to C# 10.0
When I go to my project's properties' advanced build settings, the option to change the language version is disabled. I'm not sure why it's grayed out, but I don't know how to manually change the C# version. If someone could help, that would be great, thanks!
Screenshot of the advanced build settings
Taken directly from the documentation
The compiler determines a default based on these rules:
Target framework
version
C# language version default
.NET
7.x
C# 11
.NET
6.x
C# 10
.NET
5.x
C# 9.0
.NET Core
3.x
C# 8.0
.NET Core
2.x
C# 7.3
.NET Standard
2.1
C# 8.0
.NET Standard
2.0
C# 7.3
.NET Standard
1.x
C# 7.3
.NET Framework
all
C# 7.3
C# 10 is supported only on .NET 6 and newer
You haven't provided the target framework for your project. But you likely need to retarget your project to a framework that supports C#10
You can try to edit the .csproj file by adding something like this:
<PropertyGroup>
<LangVersion>10.0</LangVersion>
</PropertyGroup>
C#10 is already the default language version if your target framework is .NET 6, provided you're not overriding it with the LangVersion entry as mentioned in other answers. If you're not targeting .NET 6 or compiling with VS/Build Tools 2022, you'll need to upgrade those first in order to have proper C#10 support.
If you are attempting to set the C# language version manually, keep in mind the default can be overridden in two locations (or programmatically): the project file (aka ProjectName.csproj), or a Directory.Build.props file (for explicitly overriding multiple projects at once). If the aforementioned props file exists, check it as well as your project file to ensure you don't have conflicting entries.
In your case, there's really no reason to manually specify the language version; just upgrade your compiler and use the default. If at that point you still find the project targeting anything < C#10, be aware that the culprit isn't necessarily confined to being the project file.
I can not change the version of C # on visual studio 2019
I tried to go to the property to access a window that normally allowed to change the version of C #
Error CS8025 The 'local functions' feature is not available in C # 4. Use version 7.0 or later.
I'm assuming you're using .Net Core. Within the .csproj file for your start-up project (executable, web, web API, whichever it is in your case), add the following:
<PropertyGroup>
<LangVersion>latest</LangVersion>
</PropertyGroup>
See the docs for more details.
Right click on your csproj in the solution explorer.
Select properties.
Select 'Build' near the top left of the screen.
Click 'Advanced' in the main window (scroll down if you can't see it).
Change language version to latest minor version.
I was not able to edit the language in the property page.
I had to add this to the csproj which was not able to build.
in the propertyGroup, right where AsseblyName is for my .netcore 3 project.
<LangVersion>8</LangVersion>
you should probably use the version according to your .net framework version, the table is here:
The compiler determines a default based on these rules:
DEFAULTS
Target framework C# language version default
.NET 6.x C# 10
.NET 5.x C# 9.0
.NET Core 3.x C# 8.0
.NET Core 2.x C# 7.3
.NET Standard 2.1 C# 8.0
.NET Standard 2.0 C# 7.3
.NET Standard 1.x C# 7.3
.NET Framework all C# 7.3
source:
https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/configure-language-version
My VSCode debugger says that I'm using c# 4. I can't find any docs about getting VSCode to switch to C# 7. I'm on Windows 10. I don't know if this is a DotNet Core issue, a VSCode issue, or an Omnisharp issue. I would appreciate someone pointing me to a set of instructions or posts that solved this problem.
A snipet from the top of my VSCode .csproj file:
<?xml version="1.0" encoding="utf-8"?> <Project ToolsVersion="4.0"
DefaultTargets="Build"
xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup> <LangVersion>4</LangVersion> </PropertyGroup>
<TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
These are my VSCode versions:
Version: 1.27.2 (user setup)
Commit: f46c4c469d6e6d8c46f268d1553c5dc4b475840f
Date: 2018-09-12T16:17:45.060Z
Electron: 2.0.7
Chrome: 61.0.3163.100
Node.js: 8.9.3 V8: 6.1.534.41
Architecture: x64
.NET Core SDK version 2.1.402 (x64)
As you've pointed out in the portion of your question where you posted the csproj, the current language version is set to 4.
<LangVersion>4</LangVersion>
You can get the latest features for C# 7.3 by setting it to <LangVersion>7.3</LangVersion>
If you merely want the C# 7.0 features, you can set the value to <LangVersion>7</LangVersion>
This document lists the (currently) valid options that can be passed to the -langversion compiler flag. If you want your project to always compile with the latest available version of C#, you can set the value to <LangVersion>latest</LangVersion> in your .csproj. Of course, this will only compile to the latest version supported by your version of the compiler.
The behavior of the default value has changed in recent versions of the compiler. The document accurate at the time of editing is this one, which states the following:
The compiler determines a default based on these rules:
Target framework
Version
C# language version default
.NET Core
6.x
C# 10.0
.NET Core
5.x
C# 9.0
.NET Core
3.x
C# 8.0
.NET Core
2.x
C# 7.3
.NET Standard
2.1
C# 8
.NET Standard
1.x/2.0
C# 7.3
.NET Framework
all
C# 7.3
You just need to update your
<PropertyGroup> <LangVersion>4</LangVersion> </PropertyGroup>
To the version you want
I have finally installed Visual Studio 2017.2 and am trying to get my first project working, but am running into some trouble that I hope to address here.
I have a very simple .NET Standard Library described as the following project file:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>netstandard1.6</TargetFramework>
</PropertyGroup>
</Project>
And a very simple .NET Framework console application that references the above .NET Standard library, and is described as the following project file:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net45</TargetFramework>
</PropertyGroup>
<ItemGroup>
<ProjectReference Include="..\Common\Common.csproj" />
</ItemGroup>
</Project>
When I build my console application, I get the following build error:
C:\Program Files\dotnet\sdk\1.0.4\NuGet.targets(97,5): error : Project Common is not compatible with net45 (.NETFramework,Version=v4.5). Project Common supports: netstandard1.6 (.NETStandard,Version=v1.6)
I saw this question and tried some of the suggestions provided there, but none of them worked. So, this appears to be a different problem. Please note that this occurs during the build of my solution and not referencing (explicit) NuGet packages in any way.
Finally, if it helps, I have a solution that demonstrates this issue here:
https://github.com/Mike-EEE/Stash/blob/master/VS2017.Multi/VS2017.dotNetFramework.sln
.NET Framework 4.5 only supports using .net standard libraries targeting .NET Standard 1.0 or 1.1. Since your library targets 1.6, the tooling does the right thing here and errors out (since your library may use APIs not available in .NET Framework 4.5). If you published the library as NuGet package and consumed it via a package reference, the package restore would error out as well (with an error saying that the package is incompatible).
There is some confusion about which .NET Standard version a .NET Framework version supports especially since there is preview tooling available ("2.0") that changes these versions. The ".NET platforms support" table in the documentation therefore contains two lines about the supported versions. In your case however, both versions limit .NET Framework 4.5 to .NET Standard 1.1.
for .net framework projects to be compatible with .net standard libraries you must acquire the NETStandard.Library from the nuget.
Now i cannot find any official resource that states exactly why this is a must, but from what i understand the NETStandard.Library has the necessary links to make a map from .NET Standard API's to .NET Framework.
If you want more info i suggest to read the official docs of NET Standard.
This is with Visual Studio 2012 Ultimate Update 3.
I have a C# project that targets .NET 3.5. This project uses a C++/CLI dll which is also compiled for .NET 3.5.
I have noticed that if the C++ dll is compiled with Platform Toolset v110, then although I can add it to the C# project, and see the types in Intellisense, the compiler itself doesn't see any of the types. It complains that they do not exist and that I am missing an assembly reference. This does not happen if it is compiled with Platform Toolset v90.
If I then re-target the C# project to .NET 4 or 4.5, then it sees the types alright. The types do exist in the assembly and can be seen in the object explorer or Ildasm.
It therefore seems that the use of Platform Toolset v110 makes it impossible to use the dll from a .NET 3.5 project, even though the dll is compiled for .NET 3.5.
Is this normal and/or documented behavior? Is there any way around this other than either downgrading the C++/CLI project to Platform Toolset v90 or upgrading the C# project to .NET 4?
As always Toolset v110 does not support any .Net version other than 4.5. Officially, to change the target framework you must change the platform toolset to a version that supports the target .Net version (e.g. Windows 7 SDK for .net 2.0-3.5 SP1). This involves changing TargetFrameworkVersion in the project file as well as switching to another platform toolset.
That said, the toolset is just a bunch of msbuild rules so you may get the the compiler to retarget the .Net version by changing the vcxproj and global msbuild rules
in project file. Olga Arkhipova from the VC++ team comes up with this:
<TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
<RealTargetFrameworkVersion>$(TargetFrameworkVersion)
</RealTargetFrameworkVersion>
Add a file to 'C:\Program Files (x86)\MSBuild\4.0\Microsoft.Common.Targets\ImportBefore
<Project ToolsVersion="4.0"
xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<TargetFrameworkVersion
Condition="'$(RealTargetFrameworkVersion)' != ''">
$(RealTargetFrameworkVersion)
</TargetFrameworkVersion>
</PropertyGroup>
</Project>