Introduction

WinUI 3 is the latest native UI platform for building modern, beautiful, and performant Windows desktop applications. As the successor to the Universal Windows Platform (UWP) XAML framework, WinUI 3 brings the power and flexibility of modern UI development to all Windows desktop applications, regardless of their packaging model. It leverages XAML and C++ for rich, visually engaging user interfaces that feel at home on Windows.

WinUI 3 empowers developers to create applications that are:

  • Modern: Adheres to the latest Windows design principles (Fluent Design).
  • Performant: Built for speed and responsiveness.
  • Consistent: Provides a unified development experience across different Windows versions.
  • Feature-rich: Offers a comprehensive set of controls and capabilities.

Getting Started with WinUI 3

Getting started with WinUI 3 involves setting up your development environment and creating your first project. The recommended IDE is Visual Studio 2022.

Prerequisites:

  • Visual Studio 2022 (with the ".NET desktop development" and "UWP development" workloads).
  • Windows 10 (version 1903 or later) or Windows 11.

Steps:

  1. Open Visual Studio Installer and ensure the necessary workloads are installed.
  2. Create a new project.
  3. Search for and select the "Windows App SDK (WinUI 3 in Desktop)" template.
  4. Configure your project name and location.
  5. Build and run your application!

You can also create WinUI 3 applications using C++.

Key Features of WinUI 3

WinUI 3 offers a robust set of features designed to enhance the developer experience and the end-user application quality:

  • Fluent Design System: Access to the latest Fluent Design controls and patterns.
  • Modern Controls: A rich library of UI controls including DataGrid, TreeView, DatePicker, TimePicker, and more.
  • Extensibility: Easy integration with existing Win32 applications.
  • Performance Optimizations: Improved rendering performance and memory management.
  • Windows App SDK Integration: Leverages the Windows App SDK for platform APIs and deployment.
  • XAML Islands: Enables embedding WinUI 3 controls into existing WinForms and WPF applications.

Code Examples

Here's a simple XAML example demonstrating a button with custom styling:

<Button Content="Click Me" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="20" Background="#0078D4" Foreground="White" Padding="10,5"/>

And a C# code-behind snippet to handle a button click:

public sealed partial class MainWindow : Window { public MainWindow() { this.InitializeComponent(); } private void MyButton_Click(object sender, RoutedEventArgs e) { // Handle button click logic here System.Diagnostics.Debug.WriteLine("Button clicked!"); } }

API References and Documentation

For detailed information on WinUI 3 controls, APIs, and best practices, please refer to the official Microsoft documentation.

Explore WinUI 3 Documentation UWP API Reference (relevant concepts)