月份：2019年2月

1. 安装.net sdk

执行命令sudo pacman -S dotnet-sdk(这里用的manjaro)

运行完后，运行dotnet --info 查看版本，显示如下，说明安装成功。

.NET Core SDK (reflecting any global.json):
 Version:   2.2.102
 Commit:    96ff75a873

Runtime Environment:
 OS Name:     manjaro
 OS Version:  
 OS Platform: Linux
 RID:         arch-x64
 Base Path:   /opt/dotnet/sdk/2.2.102/

Host (useful for support):
  Version: 2.2.1
  Commit:  878dd11e62

.NET Core SDKs installed:
  2.2.102 [/opt/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.NETCore.App 2.2.1 [/opt/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

2. 创建项目

执行命令 dotnet new web -o web 这句命令的意思是，创建一个ASP. NET Core Empty项目，并将该项目命名为web，显示一下信息说明项目创建成功

The template "ASP.NET Core Empty" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on weba/web.csproj...
  Restoring packages for /home/txl/csharp/weba/web.csproj...
  Generating MSBuild file /home/txl/csharp/weba/obj/web.csproj.nuget.g.props.
  Generating MSBuild file /home/txl/csharp/weba/obj/web.csproj.nuget.g.targets.
  Restore completed in 2.3 sec for /home/txl/csharp/web/web.csproj.

Restore succeeded.

3. 运行项目

运行dotnet build  命令，先编译下项目

Microsoft (R) Build Engine version 15.9.20.63311 for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 609.99 ms for /home/txl/csharp/weba/weba.csproj.
  webtestapi -> /home/txl/csharp/weba/bin/Debug/netcoreapp2.2/weba.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:03.70

在运行项目，dotnet run。

第一运行时可能会出现错误：

info: Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
      User profile is available. Using '/home/txl/.aspnet/DataProtection-Keys' as key repository; keys will not be encrypted at rest.
crit: Microsoft.AspNetCore.Server.Kestrel[0]
      Unable to start Kestrel.
System.InvalidOperationException: Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found.
To generate a developer certificate run 'dotnet dev-certs https'. To trust the certificate (Windows and macOS only) run 'dotnet dev-certs https --trust'.
For more information on configuring HTTPS see https://go.microsoft.com/fwlink/?linkid=848054.
   at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions, Action`1 configureOptions)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)

Unhandled Exception: System.InvalidOperationException: Unable to configure HTTPS endpoint. No server certificate was specified, and the default developer certificate could not be found.
To generate a developer certificate run 'dotnet dev-certs https'. To trust the certificate (Windows and macOS only) run 'dotnet dev-certs https --trust'.
For more information on configuring HTTPS see https://go.microsoft.com/fwlink/?linkid=848054.
   at Microsoft.AspNetCore.Hosting.ListenOptionsHttpsExtensions.UseHttps(ListenOptions listenOptions, Action`1 configureOptions)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Hosting.Internal.WebHost.StartAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String shutdownMessage)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)
   at webtestapi.Program.Main(String[] args) in /home/txl/csharp/weba/Program.cs:line 17

这个错误说明要安装一个证书，开启https，错误中已经给出提示，如果是linux系统，执行dotnet dev-certs https 命令。

如果是windows或mac系统，执行`dotnet dev-certs https –trust`。

运行dotnet dev-certs https, 出现以下问题。

Cannot find command 'dotnet dev-certs', please run the following command to install

dotnet tool install --global dotnet-dev-certs

所以，又执行dotnet tool install --global dotnet-dev-certs 命令，却又出现这个…

Tool 'dotnet-dev-certs' is already installed.

这里查了好久，发现dotnet-dev-certs是一个执行文件，位于$HOME/.dotnet/tools目录下，所以执行$HOME/.dotnet/tools/dotnet-dev-certs https，本以为没问题，结果又出现

A fatal error occurred, the required library libhostfxr.so could not be found.
If this is a self-contained application, that library should exist in [/home/txl/.dotnet/tools/.store/dotnet-dev-certs/2.2.0/dotnet-dev-certs/2.2.0/tools/netcoreapp2.2/any/].
If this is a framework-dependent application, install the runtime in the default location [/usr/share/dotnet] or use the DOTNET_ROOT environment variable to specify the runtime location.

到这里，真是有点崩溃了，于是再找之，发现需要设置环境变量DOTNET_ROOT

设置环境变量export DOTNET_ROOT=/opt/dotnet，这个目录是不是很眼熟，没错，

就是dotnet --info命令中的Bash Path的前半段。

然后在在执行命令$HOME/.dotnet/tools/dotnet-dev-certs https

The HTTPS developer certificate was generated successfully.

ok，终于看到希望了，再执行dotnet run ，成功！

项目发布，发布目标平台为linux x64，并且包含dotent 运行时，这意味着目标服务器可以不用装dotnet 环境也可以运行

dotnet publish -c Release -r linux-x64 --self-contained true