Migrate Xamarin Forms Effect to .NET MAUI

Question

For a Xamarin Forms application, I have been using a solution to track touch using code from an example out of Microsoft's Xamarin Forms Sample Project, specifically the Touch Tracking Effect sample.

I took that sample and simplified it down to just directly starting up with the BoxViewDraggingPage.xaml from App.xaml.cs and removing all other XAML files. That compiled and ran fine.

I then created a .NET Maui App with the same BoxViewDraggingPage (and the same TouchActionEventArgs.cs, TouchActionEventHandler.cs, TouchActionType.cs, and TouchEffect.cs) as was in the Xamarin Forms version.

I added the same TouchEffect.cs files that were in the sample for the specific platforms (iOS also has a TouchRecognizer.cs file)

When running it at that point I got the following:

So then I tried following the instructions for Migrating Xamarin.Forms Effects. The explanation for how Xamarin.Forms effects were set up matched perfectly, but it was unclear to me from that page what class the section titled "Effects in .NET MAUI" was replacing since it had a different class name than the previous code snippets earlier in the article. It seemed like it is replacing the FocusEvent class in the shared platform code and then specifies the platform specific code within #if platform sections (#if WINDOWS, #if __ ANDROID __, etc.) and so I am guessing that means the TouchEffect.cs files are no longer needed in the platform specific folders.

I didn't have a chance to find out if that was the case or if it works, because when I try to compile, I get:

I don't find any missing Nuget packages or assemblies when I tried searching. If I click the dot after Platform, I get the following choices, with instructions to use the navigation bar to switch contexts:

But I am already targeting net6.0-windows10.0.19041.0:

so I'm not sure why it says Not Available for that.

So, I am stuck trying to get this to work.

I am looking either for a solution to get the sample code working as it is in the Xamarin.Forms project, but for .NET MAUI (whether that be set up how the sample originally had it or how it is described in the Migrating Xamarin.Forms Effects link) - it could be that I am missing something simple in how to get that Microsoft.Maui.Controls.Compatibility.Platform.UWP piece to compile.

Or, the other possibility is that same link says that .NET MAUI Handlers can also handle this type of scenario. So if someone can show all the pieces that would need to be modified in order to do the same solution but using .NET MAUI Handlers, I am open to that. But it seems that the easiest path, though, should be to get the Effects working in .NET MAUI since everything is already written that way. I am just leaving both options open in looking for a solution.

EDIT:

OK, I figured out why the UWP portion had red squiggles under it. I figured out what "using the navigation bar to switch contexts" in the above screenshot meant. It meant I needed to select the context in the dropdown pictured below:

However, this just moves the squiggles to PlatformEffect and I cannot figure out what to do with the context or anything else to resolve that:

Answer 1

OK, I found out that PlatformEffect now inherits from Microsoft.Maui.Controls.PlatformEffect instead of the separate Platform inheritances shown in the Migrating Xamarin.Forms Effects example. That example is out of date and I didn't realize that and so it was confusing me.