Code-Behind or MVVM

[SalomezEthan]

Hi !
I'm beginner WinUI dev and I have a question.
I'd like to know when I should use pure MVVM versus code-behind for my WinUI projects.

Thanks in advance if someone responds !

[Zakariathr22]

In my opinion, the right architecture depends on your app’s complexity and how much data flows through it.

• If it’s a simple app with minimal logic and basic UI interaction, code-behind is fine, it’s fast and gets the job done.
• But if you’re building something larger, with more complex logic and significant data flow, MVVM is a better choice. It keeps your codebase clean, testable, and easier to maintain over time.

Note

It’s not just a choice between code-behind and MVVM. There are other valid approaches. For example, the WinUI Gallery app doesn’t strictly use either.
Instead, it follows a structure that organizes code by responsibility (e.g., Helpers, Pages, Samples, Controls etc.).

So the real question isn’t "Should I use MVVM or not?"
It’s: What structure makes my project simpler, easier to maintain, and testable as it grows?
Pick the architecture that best supports those goals.

[SalomezEthan]

Thank you very much for your response.
It's not easy to create a good software ahah ^^"

[AndrewKeepCoding]

Usually, I implement my apps using MVVM. However, this doesn't mean that there won't be any code-behind. My approach is to separate the projects. For example:

ToDo (WinUI 3 Project)

Views, all UI-related components or anything requiring the Microsoft.UI.xxx namespace belong here.
A specific example about code-behind could be handling a button click that opens a file picker dialog.

ToDo.Core (C# Class Library Project)

ViewModels, Models and other core logics belong here.