PdfSharpCore VS ReactiveUI

PdfSharpCore https://github.com/ststeiger/PdfSharpCore, a .NET Core port of PdfSharp, might come to the rescue as it has largely removed GDI+.

a) create PDF with https://github.com/ststeiger/PdfSharpCore and then display by using https://www.nuget.org/packages/PdfiumViewer.Updated/ - tested and works in .net 6 desktop app

PdfSharpCore has a compression feature and it's MIT licenced. https://github.com/ststeiger/PdfSharpCore

In one of my pet projects I use PdfSharpCore https://github.com/ststeiger/PdfSharpCore + HtmlRendererCore.PdfSharpCore https://www.nuget.org/packages/HtmlRendererCore.PdfSharpCore. The way it works is something like this:

GitHub - ststeiger/PdfSharpCore: Port of the PdfSharp library to .NET Core - largely removed GDI+ (only missing GetFontData - which can be replaced with freetype2)

ReactiveUI Official Website: For information on ReactiveUI, which closely integrates with DynamicData, visit the official website. This site offers extensive documentation and tutorials for both ReactiveUI and DynamicData. ReactiveUI.

ReactiveUI is based on Rx and very popular in the .Net world: https://www.reactiveui.net/.

I use PropertyChanged.Fody all the time and it works fantastically and consistently for implementing INotifyPropertyChange. It is even smart enough to understand dependencies within your get/set functions (should you choose to have custom ones) and notify that property if any of it's dependent properties change. While we are on the subject, if you are using MVVM with observables, you should really check out ReactiveUI. It is wonderful.

Personally I learned to use rx and observables by starting to use ReactiveUI combined with DynamicData for my WPF app MVVM architecture. It was maybe not to best choice out there, but I learned to work with it and some things it allows to do is awesome.

My favorite framework is Reactive UI but it's a bit more advanced than most MVVM frameworks since it uses Reactive Programming. You can still try its most basic features, though.

There is a lot of overlap between WPF and Avalonia so I would start with either one of those. Most certainly Avalonia if you plan to do cross platform dev. I would also highly recommend that you learn and conform to MVVM and dependency injection for your architecture in order to write clean, maintainable, and testable code. My recommendation is ReactiveUI. It leans heavily on more modern patterns like Reactive extensions and IObservable and it can do so much more than just MVVM. As such, it is also very similar to Angular so the concepts will transfer easily if you ever need to do web development. On a side note, Pluralsight has a nice quick course on SOLID design principles. If your code is a mess, it would be a good idea to take a course on this though learning MVVM will be a big step in the right direction.

Also, about data binding and reactivity if you really enjoy WinForms, nevar forget!! https://www.reactiveui.net

Your UI needs to bind to something that can programmatically notify it about changes, we call these things View-Models. Usually View-Models implement INotifyPropertyChanged interface (another key interface is INotifyCollectionChanged that is responsible for notifying collection views that number of items is changed and they need to update the UI accordingly). You can do that (the implementation of the interface) manually or use some library to do that for you just to cut some boilerplate code (e.g. ReactiveUI + Fody or Microsoft.Toolkit.MVVM or maybe even this or this).