https://learn.microsoft.com/zh-tw/dotnet/api/system.configuration.configuration.targetframework?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
Configuration.TargetFramework Property (System.Configuration) | Microsoft Learn
Gets or sets the targeted version of .NET when a version earlier than the current one is targeted.
property systemconfigurationmicrosoftlearn
https://brightcoding.teachable.com/courses/asp-net-core-razor-pages-the-complete-guide-net-6/lectures/42900204
07 : Project Properties Nullable / ImplicitUsings and TargetFramework
ASP.NET Core Razor Pages The Complete Guide (.NET 6)
project propertiesnullable