问题
I'm trying to create a .NET Standard 2.0 project, however on the project properties page it only has options up to .NET Standard 1.6. I went to Visual Studio > Tools > Extensions and Updates > Updates > Product Updates and upgraded Visual Studio 2017 to the latest version (15.5.4.)
I also downloaded / installed the .Net Core 2.0 SDKs from both of these urls:
https://github.com/dotnet/core/blob/master/release-notes/download-archives/2.0.0-download.md
https://www.microsoft.com/net/learn/get-started/windows?utm_expid=.-Fmi9Q05Ry2oXQgdtPElHw.0&utm_referrer=http%3A%2F%2Fwww.talkingdotnet.com%2Fwhats-new-in-net-standard-2%2F#windowscmd
For good measure I even rebooted, yet still no .NET Standard 2.0 option. What gives?
C:\WINDOWS\system32>dotnet --info .NET Command Line Tools (2.1.4)
Product Information: Version: 2.1.4 Commit SHA-1 hash: 5e8add2190
Runtime Environment: OS Name: Windows OS Version: 10.0.16299 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\2.1.4\
Microsoft .NET Core Shared Framework Host
Version : 2.0.5 Build : 17373eb129b3b05aa18ece963f8795d65ef8ea54
回答1:
It turns out that someone had put a global.json file at the root of our repo that was hard-coding the SDK to a 1.x preview version. Once I updated that to 2.1.4, I started getting the .NET Standard 2.0 project option!
回答2:
Go to Windows "App and Features" or "Install and Remove Programs" and make sure you have .NETCore SDK (x64) and or (x86). You may have only installed the (x64) and not the (x86). Try changing your project target to x64 and x86.
Refer to this article for installing .NET Standard 2.0
https://blogs.msdn.microsoft.com/benjaminperkins/2017/09/20/how-to-install-net-standard-2-0/
回答3:
When I click on "Install Other Frameworks..." in project properties, it takes me to this page:
https://blogs.msdn.microsoft.com/benjaminperkins/2017/09/20/how-to-install-net-standard-2-0/
And it appears that the installer on that page (dotnet-sdk-2.1.4-windows-x64-installer) is different than the one in the other links you have tried.
Also, be sure that all instances of Visual Studio are closed when you install the SDK.
来源：https://stackoverflow.com/questions/48449553/cant-get-net-standard-2-0-installed