Experiment to see if I can write Custom Actions in .NET 7.
TestMSI is a Wix4 installer which calls 2 custom actions.
CppCustomAction is a default sample C++ custom action. CustomAction is a .NET 7 Custom Action.
After compiling CustomAction it needs to be published with
dotnet publish /p:NativeLib=Shared -r win-x64 -c release
Before building the TestMSI project, which reads it from the published location.