1、应用地址池设为无托管代码
一、提示：关于IIS上运行ASP.NET Core 站点的“HTTP 500.19”错误
安装dotnet-hosting-3.1.2-win.exe
ASP.NET Core 3.1 Runtime (v3.1.2)下载地址：
https://download.visualstudio.microsoft.com/download/pr/dd119832-dc46-4ccf-bc12-69e7bfa61b18/990843c6e0cbd97f9df68c94f6de6bb6/dotnet-hosting-3.1.2-win.exe
二、HTTP Error 500.30 - ASP.NET Core app failed to start
web.config中把hostingModel改为：outofProcess
