Creating Cross-Platform Apps with Xamarin: A Complete Guide for Modern Mobile Development

📘 Chapter 6: Publishing Your Xamarin App and Transitioning to .NET MAUI

🧭 What You’ll Learn

In this chapter, you’ll learn how to:

• Prepare your Xamarin app for publishing on the Google Play Store and Apple App Store
• Create signing keys, provisioning profiles, and distribution builds
• Understand app store requirements, icons, and metadata
• Use App Center, Azure DevOps, or CI/CD for automated builds
• Migrate or transition your app from Xamarin.Forms to .NET MAUI
• Understand changes between Xamarin and .NET MAUI
• Prepare for the future of cross-platform development on .NET

🚀 Publishing Xamarin Apps

✅ General Requirements

Before publishing:

• Finalize app name, icon, splash screen
• Verify bundle identifiers (iOS) and application IDs (Android)
• Set build mode to Release
• Enable app linking to reduce size
• Set proper version numbers and build codes

📦 Packaging Android APK/AAB

✅ Steps:

1. Right-click your Android project → Properties
2. Under Android Options, check:
• Configuration: Release
• Linker: SDK Assemblies Only
• Generate Signed APK/AAB
3. Set Application ID in AndroidManifest.xml
4. Add version info:

xml

<manifest android:versionCode="1" android:versionName="1.0" />

5. Generate keystore:

bash

keytool -genkey -v -keystore myreleasekey.keystore -alias mykey -keyalg RSA -keysize 2048 -validity 10000

6. Sign APK/AAB using Visual Studio or Gradle

📱 Packaging for iOS

✅ Prerequisites:

• Mac with Xcode installed
• Apple Developer Account
• Created App ID, Provisioning Profile, and Distribution Certificate

✅ Steps:

1. In Info.plist: Set version and bundle identifier
2. Configure Release > iPhone build settings
3. Sign in to Apple Developer Portal and download the profile
4. Archive your app using Visual Studio for Mac
5. Use Application Loader or Xcode Organizer to submit

💼 App Store Submission Checklists

🔄 Automate with CI/CD and App Center

Microsoft App Center allows you to:

• Build Xamarin apps in the cloud
• Run tests on physical devices
• Distribute builds to testers
• Monitor crashes and usage

✅ Sample YAML for GitHub Actions (Android)

yaml

name: Xamarin Android Build

on:

  push:

    branches:

      - main

jobs:

  build:

    runs-on: macos-latest

    steps:

    - uses: actions/checkout@v2

    - name: Install .NET

      uses: actions/setup-dotnet@v1

      with:

        dotnet-version: 6.0.x

    - name: Build Android

      run: msbuild MyApp.Android/MyApp.Android.csproj /p:Configuration=Release

💡 .NET MAUI: The Future of Xamarin

.NET MAUI (Multi-platform App UI) is the evolution of Xamarin.Forms, part of .NET 6 and beyond.

It enables development for:

• iOS
• Android
• macOS
• Windows (WinUI)

All from a single project and codebase, with unified APIs, better performance, and modern tooling.

🧬 Xamarin.Forms vs .NET MAUI

🔁 Migrating Xamarin.Forms to .NET MAUI

✅ Migration Strategy

1. Update to Xamarin.Forms 5 (last stable)
2. Audit third-party packages for MAUI support
3. Move logic to .NET Standard or .NET 6 compatible libraries
4. Start a new .NET MAUI project:

bash

dotnet new maui -n MyApp

5. Port your XAML pages and ViewModels
6. Refactor platform-specific code into Platforms/ folders
7. Test on all four platforms (Windows, Android, iOS, macOS)

✅ Example: Platform Structure in .NET MAUI

MyApp/

├── Platforms/

│   ├── Android/

│   ├── iOS/

│   ├── macOS/

│   └── Windows/

├── Resources/

│   ├── Fonts/

│   ├── Images/

├── MainPage.xaml

├── App.xaml.cs

✅ Xamarin.Forms to MAUI Snippets

Xamarin.Forms:

csharp

MainPage = new NavigationPage(new HomePage());

.NET MAUI:

csharp

MainPage = new AppShell();

🔧 Tooling for MAUI

✅ Summary Table: Publishing vs Migration

✅ Summary

In this chapter, you learned how to:

• Package and publish your Xamarin app for Android and iOS
• Handle app signing, versioning, and deployment
• Automate your release process using CI/CD
• Monitor and distribute apps with App Center
• Begin your migration from Xamarin.Forms to .NET MAUI
• Understand the differences, advantages, and future scope of MAUI

Xamarin is stable—but MAUI is the future. As .NET unifies under one framework, MAUI offers an exciting evolution for cross-platform development.