Build a WinUI app with an AI coding assistant

AI coding assistants can create a working app quickly, but they can also combine APIs from different generations of Windows development. A response might look convincing while mixing WinUI 3 with UWP, WPF, WinUI 2, or .NET MAUI.

In this tutorial, you use an AI coding assistant to build Task Tally, a small WinUI 3 task app. More importantly, you learn how to direct the assistant, inspect its work, and verify the result against Microsoft Learn.

The tutorial uses this cycle:

Ask → Generate → Build → Inspect → Verify → Refine

The assistant can write code and explain it, but the compiler, the running app, and the current documentation remain your sources of truth.

What you build

Task Tally lets a user:

• Add and delete tasks.
• Mark tasks complete.
• Save tasks in local app storage.
• Resize the window without losing access to commands.
• Use the app with a keyboard and accessibility tools.

You use C#, WinUI 3, the Windows App SDK, and the MVVM Toolkit. The app is packaged with MSIX for local development.

What you learn

• Write requirements that keep generated code within WinUI 3.
• Break a feature into prompts that you can build and verify independently.
• Inspect generated project files, namespaces, controls, and data binding.
• Verify Windows APIs against Microsoft Learn.
• Recognize common AI-generated mistakes in Windows app code.
• Test generated code instead of accepting it because it looks plausible.

Prerequisites

Complete Quick start: Create your first WinUI 3 app first. You need:

• Windows 10 version 1809 (build 17763) or later.
• Developer Mode enabled.
• Visual Studio 2026 with the WinUI application development workload, or the .NET 10 SDK and WinUI templates.
• An AI coding assistant that can read and edit files in your project.

You don't need previous WinUI experience. The prompts in this tutorial are tool-neutral, so adapt their command wording to your assistant.

Important

Review changes before you accept them. Don't paste credentials, private source code, personal data, or other sensitive information into a service that isn't approved for that data.

Define the app and write the first prompt