.NET MAUI: The Future of Cross-Platform Development

Introduction:

.NET Multi-platform App UI (.NET MAUI) is a versatile framework that enables developers to build native applications for both mobile and desktop platforms using C# and XAML. With .NET MAUI, you can create apps for Android, iOS, macOS, and Windows, all from a unified codebase, ensuring efficiency and consistency across multiple platforms.

.NET MAUI is an open-source framework and the next step in the evolution of Xamarin.Forms. It extends beyond mobile app development to include desktop platforms, offering rebuilt UI controls designed for improved performance and greater flexibility. If you’re familiar with Xamarin.Forms for creating cross-platform UIs, you’ll find .NET MAUI shares many concepts, while also introducing new features and enhancements.

With .NET MAUI, you can develop multi-platform applications within a single project, but it also provides the flexibility to include platform-specific code and resources where needed. A core objective of .NET MAUI is to allow developers to centralize most of their app logic and UI design within a unified codebase, streamlining the development process.

 

Who .NET MAUI is for

.NET MAUI is designed for developers aiming to:

• Build cross-platform applications using XAML and C# with a unified codebase in Visual Studio.
• Reuse UI layouts and designs across multiple platforms.
• Share business logic, testing, and code seamlessly across platforms.

 

Why Choose .NET MAUI?

• Unified Development: Write once and deploy across multiple platforms.
• Native Performance: MAUI apps compile to native code, ensuring high performance and platform-specific capabilities.
• Rich UI: Leverage platform-native UI elements or build custom designs with XAML.
• Strong Ecosystem: Integrated with the .NET ecosystem, including libraries, tools, and cloud services.

 

Key Features of .NET MAUI

• Single Project Structure: Manage resources and platform-specific code from one project.
• Hot Reload: Make changes to your UI and see them instantly without restarting the app.
• Cross-Platform APIs: Access device features like sensors, GPS, and cameras through a unified API.
• XAML and MVVM: Build intuitive UIs with declarative XAML and implement logic with the Model-View-ViewModel pattern.

 

Setting Up Your Development Environment

• Install Visual Studio 2022: Ensure you select the “.NET Multi-platform App UI development” workload.
• Set Up Dependencies: Install the required SDKs for the platforms you plan to target (Android, iOS, etc.).
• Create a New Project: Open Visual Studio, select "Create a new project," and choose the .NET MAUI App template.

 

Building Your First .NET MAUI App

Project Structure

A .NET MAUI project includes:

• MainPage.xaml: Define your UI.
• MainPage.xaml.cs: Add behavior to your UI.
• Platforms Folder: Manage platform-specific resources and code.

 

Creating UI with XAML

Here’s an example of a simple XAML UI:

Adding Business Logic

Handle button clicks in MainPage.xaml.cs:

How .NET MAUI works

.NET MAUI consolidates the APIs of Android, iOS, macOS, and Windows into a unified framework, delivering a seamless "write-once, run-anywhere" experience for developers. It also provides full access to the specific features of each native platform, allowing for greater customization when needed.

Starting with .NET 6 and beyond, several platform-specific frameworks are available for building applications, such as .NET for Android, .NET for iOS, .NET for Mac Catalyst, and the Windows UI 3 (WinUI 3) library. These frameworks all leverage the Base Class Library (BCL), which abstracts platform-specific details and provides a consistent coding experience. The BCL relies on .NET runtime for executing code. For platforms like Android, iOS, and macOS, this runtime is implemented via Mono, while Windows uses .NET CoreCLR as its execution engine.

The BCL enables shared business logic across different platforms, but platform-specific UI development remains a challenge. Each platform has unique methods for defining and managing user interfaces, requiring separate codebases for Android, iOS, macOS, and Windows if you rely solely on platform-specific frameworks like .NET for Android or WinUI 3. This approach increases maintenance complexity.

.NET MAUI solves this by offering a single framework to create user interfaces for both mobile and desktop platforms. By doing so, it eliminates the need for managing separate codebases for different platforms. Here's how developers can get started:

Share Code and Logic Across Platforms: With .NET MAUI, you can centralize most of your application’s logic and UI definitions in one project. While platform-specific code and resources can still be added when necessary, the primary goal is to maximize code reuse across all target platforms.

One of the core objectives of .NET MAUI is to streamline app development by enabling a single codebase to handle both the app’s UI and logic, ensuring consistency across platforms while simplifying maintenance.

In a .NET MAUI application, the code primarily works with the .NET MAUI controls and APIs (1). These APIs serve as a bridge to interact with the underlying native platform features (3). Additionally, if needed, your app code can directly utilize platform-specific APIs (2).

.NET MAUI applications can be developed on both Windows and macOS systems and are compiled into native app packages:

• Android: .NET MAUI apps written in C# are first compiled into an intermediate language (IL) and later just-in-time (JIT) compiled into native assembly during app execution.
• iOS: Apps for iOS are fully ahead-of-time (AOT) compiled, transforming C# code directly into native ARM assembly, resulting in faster performance and smaller app sizes.
• macOS: Leveraging Apple's Mac Catalyst, .NET MAUI apps built for iOS can be adapted to macOS. This approach combines UIKit with desktop-specific AppKit and platform APIs as necessary.
• Windows: Apps designed for Windows with .NET MAUI utilize the Windows UI 3 (WinUI 3) library, enabling developers to create truly native Windows desktop applications.

This architecture ensures that .NET MAUI apps deliver native performance and access platform-specific features, all while maintaining a single codebase.

 

Best Practices for .NET MAUI Development

• Follow the MVVM pattern for better maintainability.
• Organize your project structure for scalability.
• Use platform-specific code only when necessary.
• Write unit tests for your business logic and platform tests for critical features.

 

Cross-platform APIs for device features

.NET MAUI offers a unified way to work with native device features through its cross-platform APIs. It simplifies access to key device functionalities, including:

• Accessing hardware sensors like accelerometers, compasses, and gyroscopes.
• Monitoring network connectivity status and detecting any changes.
• Retrieving details about the device where the app is running.
• Enabling text copying and pasting across applications via the system clipboard.
• Selecting single or multiple files directly from the device.
• Storing sensitive data securely using key-value pairs.
• Leveraging text-to-speech capabilities to convert written text into spoken words.
• Supporting browser-based authentication flows, with callbacks to app-specific registered URLs.

 

Conclusion

.NET MAUI is a powerful tool for creating modern, cross-platform applications. By leveraging its unified development model, rich features, and robust ecosystem, you can deliver high-quality apps efficiently.