.NET MAUI : Runs on multiple platforms in one project (iOS, Android, and Windows)

Labels MAUI Xamarin

The name MAUI stands for .NET Multi-platform App UI. Many IT companies struggle with deciding whether to migrate from XAMARIN or to start from scratch with a new hybrid application. You should not make any mistakes, better choose to move to MAUI. Prior to migration, you must understand what the main project file and platform specific changes are that differ from XAMARIN. It is not the purpose of this article to explain migration, but you should know before you migrate what the main changes have been to the project files in MAUI. To gain a deeper understanding of MAUI project files, let's follow me one by one in this article

Prerequisites
Visual Studio 2022 with the MAUI workload installed
Xamarin, MAUI Support for Visual Studio Mac
As we all know, Microsoft supports MAUI from Visual Studio 2022 latest version in Macs and Windows. Several people asked me if I could install Visual 2022 from my Mac, and if so, could it keep creating/modify Xamarin Forms, and the answer is yes, which means Microsoft continues to support Xamarin for now, so the latest Visual studio 2022 has both Xamairn and MAUI project templates, so if you are starting a new project, choose MAUI as the template, because it has wonderful features.


MAUI Project File
A user can build a .NET MAUI application for Android, iOS, macOS, and Windows in one project file. Xamarin Forms uses different project files for Individual platforms. the .NET MAUI application is focused on Android, iOS, macOS, and Windows, simplifying and standardizing the cross-platform development experience for all four platforms.

MAUI SDK-style format
The .NET SDK is the base SDK for .NET. Projects associated with the other SDKs have access to all the .NET SDK properties. The default .Net Framework project is not SDK style and the default .Net Core, MAUI and .Net Standard project will be SDK style by default, Right click on your project and see the project file Below is the code for the MAUI project file, which is an XML file. The Sdk attribute defines which SDK is targeted.

All project-level properties are enclosed within the PropertyGroup node. ItemGroup node holds dependencies, such as Project(s) referenced, NuGet package(s) added, Resource definitions, etc, will check line by line here
Multiple Target Platform
MAUI is multi-targeting by design, hence the TargetFrameworks list (which is separated by a semicolon).The Target Framework Monikers are all prefixed with net7.0-.The reason for this is that there is only one BCL.The actual platform is then specified (iOS, Android, MacCatalyst, and Windows).

Use MAUI & Output Type

UseMAUI: UseWPF introduced in .NET Core 3 is familiar to developers with WinForms/WPF backgrounds.Whether or not to include references to MAUI libraries is controlled by the UseMAUI property.The MSBuild pipeline is also altered to correctly process a MAUI project and related files. Instead of referencing NuGet packages, set the UseMAUI property to true to add MAUI packages

SingleProject
The SingleProject tag represents .NET MAUI's main design goal, multi-targeting.

RootNamespace
RootNamespace, the root namespace for the types contained within this project.(My Project name - NewProjectFile7._0)

ImplicitUsings
.NET 6 introduces implicit namespace support for C# projects. To reduce the amount of using directives boilerplate in .NET C# project templates, namespaces are implicitly included by utilizing the global using feature introduced in C# 10. When you create a new .NET 6 and above project it will enable this new property

Mobile App Shared Configuration (App manifest)
Since we only have one project, we don't have to manage different platform configurations. We are able to configure in one project and we are not required to manage different platform configurations.

MAUI Image

MAUI Image is a newly introduced node, which helps in including SVG images and is based on the popular resize component, which resizes the images internally based on the platform.Provides developers with a much easier process for including images across multiple platforms.

In a .NET Multi-platform App UI (.NET MAUI) app project, images can be specified in a single location in your app project, and at build time they can be automatically resized to the correct resolution for the target platform and device, and added to your app package. This avoids having to manually duplicate and name images on a per platform basis. By default, bitmap (non-vector) image formats, including animated GIFs, are not automatically resized by .NET MAUI.

.NET MAUI images can use any of the standard platform image formats, including Scalable Vector Graphics (SVG) files

MAUI Icon
An app icon can be specified in a single location in your .NET Multi-platform App UI (.NET MAUI) project. Your app package can automatically resize this icon to the appropriate resolution for the target platform and device at build time.

By doing this, it will be possible to avoid having to duplicate and name app icons on a platform-by-platform basis. .NET MAUI does not automatically resize bitmap (non-vector) image formats.


Maui Splash Screen
At build time, a splash screen can be automatically resized to the correct resolution for the target platform and device, and added to the app package for a .NET MAUI app project. This eliminates having to duplicate and name splash screens on a platform-by-platform basis.


SVG Image convert to PNG
SVG files are converted to PNG files by NET MAUI. When adding an SVG file to your .NET MAUI app project, it should be referenced from XAML or C# with a .png extension. SVG files should only be referenced in project files.

MAUI Shared Application Setting
On the below screen, you will see that .NET MAUI project settings are shared among all target mobile platforms.

• Application Title - It is the name that appears as the Title in installed apps.
• Application ID - the unique identifier of the application in reverse domain name format, for example com.msdevbuild.maui.
• Application ID (GUID) - The identifier of the application in GUID format.
• Application Display Version - The version of the application. This should be a single digit integer. Defaults to 1.

Platform Specific Configuration
You can add all your platform specific configurations for iOS, Android, Windows and Mac by selecting the section. This was previously done in a platform-specific project in an target project, but now it can be done in a shared project configuration.


Platform-specific code
A .NET MAUI app project contains a Platforms folder, with each child folder representing a platform that .NET MAUI can target, The folders for each platform contain platform-specific resources, and code that starts the app on each platform and there are platform-specific configuration files for every platform, like the App manifest, info.plist, and other configuration files.


Summary
I hope that this article helps you to understand how you can create one project for multiple platforms. In case you missed my previous article, you can refer to the links below.

Xamarin MAUI: First iOS, Android and Windows Mobile App using Visual studio 2022