Can I specify a target framework based on the os?

Question

I have a public library used by various applications. There are four target frameworks in the library: netstandard 2.0 netframework 4.7.2 netframework 4.0 netframework 2.0.

After updating to the latest version of vs. mac, the above error occurred.

The exact cause of the problem is unknown, but if you look at it simply, you can compile it separately for each OS.
I wonder if there is such a function.

Answer 1

Hi @Taeo Kim , 

Welcome to Microsoft Q&A! 

Which version of Visual Studio are you using? 

For .NET Framework 4.7.2, please go to your Visual Studio Installer > Modify > Individual components > ensure that “.NET Framework 4.7.2 targeting pack” and “.NET Framework 4.7.2 SDK” are checked. 

 

For .NET Framework 4.0, it has ended for support and its developer pack is not available currently.

Alternatively, you can add a reference to Microsoft.NETFramework.ReferenceAssemblies.net40 by right-clicking on project > Manage NuGet Packages > Browse > search “Microsoft.NETFramework.ReferenceAssemblies.net40” > install it.

Then, rebuild your solution. 

For more details, please refer to: Build apps against reference assemblies.

 

For .NET Framework 2.0, please type “Turn Windows features on or off“ in the start search box > select “.NET Framework 3.5 (includes .NET 2.0 and 3.0)” check box > OK > wait for installing > restart computer.

Sincerely,

Anna

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