.NET Multi-platform App UI, or .NET MAUI, is a cross-platform development framework from Microsoft for building apps that targets both mobile and desktop form factors on Android, iOS, macOS, Windows, and Tizen. It is one of a number of cross-platform frameworks available on the market.

Before discussing cross-platform technologies, let’s review the scope of application development first. This review will help us to understand the various cross-platform frameworks better.

Generally, software development can be divided into two categories – systems programming and application programming. Application programming aims to produce software that provides services to the user directly, whereas systems programming aims to produce software and software platforms that provide services to other software. In the .NET domain, the development of the .NET platform itself belongs to systems programming, whereas application...

Before we dive into the details of .NET MAUI, let’s have an overview of the .NET landscape. This is a section for those who are new to .NET. If you are a .NET developer, you can skip this section.

Since Microsoft introduced the .NET platform, it has evolved from a proprietary software framework for Windows to a cross-platform and open-source platform.

There are many ways to look at the .NET technology stack. Basically, it contains the following components:

• Common infrastructure (compiler and tools suite)
• Base Class Library (BCL)
• Runtime (WinRT or Mono)

.NET Framework

The history of .NET started with .NET Framework. It is a proprietary software framework developed by Microsoft that runs primarily on Microsoft Windows. .NET Framework started as a future-oriented application framework to standardize the software stack in the Windows ecosystem. It is built around the Common Language Infrastructure (CLI) and...

As we mentioned in the previous section, Xamarin was part of the Mono project and was an effort to support .NET on Android, iOS, and macOS. Xamarin exports the underlying operating system features to the .NET runtime. Xamarin.Forms is the cross-platform UI framework of Xamarin. .NET MAUI is an evolution of Xamarin.Forms. Before we discuss .NET MAUI and Xamarin.Forms, let us review the following diagram of Xamarin implementations on various platforms.

Figure 1.1: Xamarin implementations

Figure 1.1 shows the overall architecture of Xamarin. Xamarin allows developers to create native UIs on each platform and write business logic in C# that can be shared across platforms.

With the .NET unification, Xamarin has become a part of the .NET platform, and Xamarin.Forms is integrating with .NET in the form of .NET MAUI.

.NET MAUI is a first-class .NET citizen with the namespace Microsoft.Maui.

Making the move to .NET MAUI is also an opportunity for Microsoft to redesign and rebuild Xamarin.Forms from the ground up and tackle some of the issues that have been lingering at a lower level. Compared to Xamarin.Forms, .NET MAUI uses a single project structure, supports hot reloads better and supports the MVU and Blazor development patterns.

Figure 1.2 shows an architecture diagram of .NET MAUI; you can find it in the Microsoft documentation. From Figure 1.2, we can see that there is a common BCL for all supported operating systems. Under the BCL, there are two runtimes...

.NET 8 introduced many new changes, and here we will review the aspects related to .NET MAUI.

Native AOT support for iOS-like platforms

.NET 8 introduces native AOT support for iOS-like platforms, allowing the building and running of .NET iOS and .NET MAUI applications on various platforms. Preliminary testing shows a 40% disk size decrease for .NET iOS apps and a 25% increase for .NET MAUI iOS apps using native AOT. However, as this is only the first step in support, performance conclusions should not be drawn yet. Native AOT support is an opt-in feature for app deployment, while Mono remains the default runtime for development and deployment.

.NET MAUI extension of Visual Studio Code

Although still in its preview stage, Visual Studio Code now offers a .NET MAUI extension, making it available for use in .NET MAUI development. The .NET MAUI extension is a new Visual Studio Code extension that lets you develop and debug your...

In this section, we will introduce the development environment setup in Visual Studio and Visual Studio Code.

Using Visual Studio

Both Windows and macOS can be used for.NET MAUI development, but you won’t be able to build all the targets with only one of them. You will need both Windows and Mac computers to build all the targets. In this book, the Windows environment is used to build and test Android and Windows targets, while iOS and macOS targets are built on a Mac computer.

.NET MAUI apps can target the following platforms:

• Android 5.0 (API 21) or higher
• iOS 11 or higher
• macOS 10.15 or higher, using Mac Catalyst
• Windows 11 and Windows 10 version 1809 or higher, using Windows UI Library (WinUI) 3

.NET MAUI Blazor apps use the platform-specific WebView control, so they have the following additional requirements:

• Android 7.0 (API 24) or higher
• iOS 14 or higher
• macOS 11 or...

In this chapter, we explored topics related to .NET MAUI and Xamarin, discussing various cross-platform technologies in comparison to .NET MAUI. This analysis provided insight into the advantages and disadvantages of different frameworks. Additionally, we compared the JavaScript and C# ecosystems, as most cross-platform frameworks utilize these languages. By introducing the .NET landscape and the available cross-platform frameworks, you now have a comprehensive understanding of the essentials before delving into the world of .NET MAUI.

In the next chapter, we will explore how to build a .NET MAUI application from scratch.

• Avalonia UI and MAUI – Something for everyone: https://avaloniaui.net/
• .NET MAUI – You can find more information about .NET MAUI in the Microsoft official documentation: https://docs.microsoft.com/en-us/dotnet/maui/
• KeePass – The official website for KeePass can be found at: https://keepass.info/

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