我下载了https://download.visualstudio.microsoft.com/download/pr/19b0ea97-68b0-49e7-8d77-5d87f703f3d6/81d7c9b2fb74070fcaa0bf0e087c5486/dotnet-runtime-3.1.3-win-x86.zip，发现和 C:\Downloads\net\host 和 \shared\ 里一样的东西

在windows7 32上 dotnet --info 和都成功了 但把Program.cs的内容替换成E708.cs的内容后 C:\Downloads\net>cd clrversion C:\Downloads\net\clrversion>dotnet run 'dotnet' 不是内部或外部命令，也不是可运行的程序 或批处理文件。 C:\Downloads\net\clrversion>..\dotnet run A fatal error occurred. The required library hostfxr.dll could not be found. If this is a self-contained application, that library should exist in [C:\Downloads\net\clrversion\bin\Debug\netcoreapp 3.1\]. If this is a framework-dependent application, install the runtime in the global location [C:\Program Files\dotnet] or use the DOTNET _ROOT environment variable to specify the runtime location or register the runtime location in [HKLM\SOFTWARE\dotnet\Setup\Installed Versions\x86\InstallLocation]. The .NET Core runtime can be found at: - https://aka.ms/dotnet-core-applaunch?missing_runtime=true&arch=x86&rid=win7-x86 是还需要装runtime吗? 改成 Console.WriteLine("OS : " + Environment.OSVersion); Console.WriteLine("CLR: " + Environment.Version); 也是一样的效果

下载了 https://download.visualstudio.microsoft.com/download/pr/76cb2134-1826-4921-82f6-fb6bab2fc166/ed8ed477eb7518d30e964c4213b3f6b7/dotnet-sdk-3.1.201-win-x86.zip，在里面没看到csc.exe啊

https://dotnet.microsoft.com/download/dotnet-core/3.1 上哪个是编译cs的?

运行时间比较长，csc 有类似c++ -O3的选项吗？ c:\Windows\Microsoft.NET\Framework\v4.0.30319>timer E708 Timer 9.01 : Igor Pavlov : Public domain : 2009-05-31 S(100,000,000,000,000) 28,---,---,---,---,109 Kernel Time = 1.388 = 0% User Time = 1024.474 = 99% Process Time = 1025.862 = 99% Global Time = 1031.804 = 100%