Upgrade Assistant (Microsoft Tool)

The .NET Upgrade Assistant is a command-line tool from Microsoft that helps migrate older .NET applications to newer versions, including:

• Xamarin.Forms → .NET MAUI

• .NET Framework → .NET Core / .NET 6+

• .NET Standard → .NET 6+ libraries

It helps automate tedious upgrade steps and provides guided prompts for manual steps.

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🧰 How to Install It

Open a terminal or command prompt and run:

bash

dotnet tool install -g upgrade-assistant

To update it later:

bash

dotnet tool update -g upgrade-assistant

To check version:

bash

upgrade-assistant --version

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🚀 How to Use It for Xamarin.Forms to MAUI

1. Navigate to your Xamarin.Forms project folder:

   bash
   
   cd path/to/MyXamarinApp
   

2. Run the assistant:

   bash
   
   upgrade-assistant upgrade MyXamarinApp.csproj
   

   Replace MyXamarinApp.csproj with the actual project file name.

3. The assistant will:

   • Detect the Xamarin.Forms project

   • Ask you which upgrade path to take

   • Guide you step-by-step through:

     • SDK-style project conversion

     • NuGet package updates

     • Target framework change to .NET 6/7/8

     • Namespace and code cleanup suggestions

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🧭 What You’ll See During the Process

The assistant presents steps like:

vbnet

Step 1 of 9: Back up project
Step 2 of 9: Convert project file to SDK-style
Step 3 of 9: Update target framework to net8.0
Step 4 of 9: Update NuGet packages
Step 5 of 9: Analyze and upgrade code
...
Continue? (y/n)

You can accept or skip each step.

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⚠️ Limitations to Know

❌ Not Fully Automated	📌 You Must Manually Handle
Custom Renderers	Rewrite to use Handlers
UI behavior differences	Review and fix layout issues
Platform-specific code	Move into Platforms/ folders
Unsupported packages	Replace or refactor

Resources

• Official Microsoft Docs:
  🔗 Xamarin to MAUI Migration Guide

• Upgrade Assistant GitHub:
  🔗 https://github.com/dotnet/upgrade-assistant

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✅ Best Practice Tips

• Back up your Xamarin project before starting.

• Try migrating to .NET 8 MAUI, which is the most stable and supported version.

• Use source control (Git) to track changes.

• Test on all platforms (iOS, Android, Windows).

Upgrading a Xamarin.Forms app to .NET MAUI cannot be fully automated, but Microsoft provides tools and guidance to help automate parts of the migration process.

Here’s a breakdown of what can be done automatically vs. manually, and a practical plan to upgrade your Xamarin.Forms app to .NET MAUI:

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🔧 Tools You Can Use

✅ Upgrade Assistant (Microsoft Tool)

Microsoft's .NET Upgrade Assistant helps migrate Xamarin.Forms projects to .NET MAUI. It automates several steps, but you will still need to do some manual refactoring.

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🧭 Step-by-Step Plan

✅ Step 1: Install Upgrade Assistant

bash

dotnet tool install -g upgrade-assistant

✅ Step 2: Run the Upgrade Assistant

bash

upgrade-assistant upgrade MyXamarinApp.csproj

This tool will:

• Convert the project to SDK-style format

• Update the target framework to .NET 6+

• Reference Microsoft.Maui packages instead of Xamarin

• Migrate NuGet packages (when possible)

• Identify unsupported APIs

Note: This works best for simple projects. Larger projects will need significant manual adjustments.

 What’s Handled Automatically?

✅ Automated	❌ Manual Required
Project file upgrade	Custom renderers / platform-specific code
NuGet package version updates	3rd-party packages not MAUI-compatible
Code file reorganization (partial)	Dependency Injection updates
Some namespace updates	UI adjustments due to control changes

📘 Manual Migration Tasks

After running the tool, manually review and fix:

1. Namespaces

   • using Xamarin.Forms; → using Microsoft.Maui.Controls;

2. Custom Renderers → Handlers (in MAUI)

   • Rewrite custom renderers as handlers if necessary.

3. Dependency Injection

   • Replace DependencyService with .NET MAUI’s ServiceCollection and DI.

4. UI Differences

   • Some controls have changed behavior or APIs. Double-check layouts and styling.

5. Platform-Specific Code

   • Move platform-specific code into .Platforms/Android, .Platforms/iOS, etc.

6. Third-Party Packages

   • Some Xamarin packages may not yet support MAUI—look for updated versions or alternatives.

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📂 Project Structure Changes

MAUI has a single project structure:

MyApp/
├── MainPage.xaml
├── Platforms/
│   ├── Android/
│   ├── iOS/
│   └── Windows/
├── Resources/
└── MauiProgram.cs

This consolidates multiple platform projects into one SDK-style project.

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🧪 Testing

• After migration, test on all target platforms (Android, iOS, Windows).

• Pay special attention to navigation, layouts, and custom UI components.

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✅ When to Migrate?

If your app is actively maintained and you're planning to add new features, migrating to MAUI is recommended since Xamarin.Forms is no longer under active development (support ended in May 2024).