MAUI Android Preview: Getting Started with Android Development

Introduction

Welcome to this guide on developing Android applications using .NET MAUI (Multi-platform App UI). .NET MAUI is an open-source, cross-platform framework for creating native mobile and desktop applications with C# and XAML from a single, shared codebase. This tutorial focuses on the Android platform, providing you with the foundational knowledge to build and test your MAUI apps on Android devices and emulators.

Example of a .NET MAUI application running on Android.

By the end of this tutorial, you will be able to set up your development environment, create a basic MAUI application, deploy it to an Android emulator, and understand the basic workflow for Android development with MAUI.

Prerequisites

Before you begin, ensure you have the following installed on your development machine:

• Visual Studio 2022 with the ".NET Multi-platform App UI development" workload installed. Ensure you have the latest version.
• .NET SDK (version 6.0 or later, typically installed with Visual Studio).
• Android SDK and necessary build tools. These are usually installed as part of the MAUI workload in Visual Studio.
• Java Development Kit (JDK).

Setting Up Your Development Environment

Visual Studio 2022 is the primary IDE for .NET MAUI development. The workload automatically configures the necessary SDKs and emulators.

Configuring Android SDK and Devices

Visual Studio's Android SDK Manager allows you to manage your installed SDK platforms and tools. You can access it via:

1. In Visual Studio, go to Tools > Android > Android SDK Manager.
2. Ensure you have at least one Android SDK Platform installed (e.g., Android 12.0 - API Level 31 or higher).
3. Navigate to the SDK Tools tab and ensure Android Emulator and Android SDK Build-Tools are installed and up-to-date.

Creating an Android Virtual Device (AVD)

To run your app without a physical device, you'll need an Android emulator.

1. In Visual Studio, go to Tools > Android > Android Device Manager.
2. Click + New Device.
3. Select a device profile (e.g., Pixel 5) and a target API level (matching one of your installed SDK Platforms).
4. Configure additional settings as needed and click Create.
5. Once created, you can start the emulator by clicking the play icon next to it in the Device Manager.

Creating a New MAUI App

Let's create a simple MAUI application to test our setup.

1. Open Visual Studio 2022.
2. Click Create a new project.
3. Search for ".NET MAUI" and select the .NET MAUI App template. Click Next.
4. Enter a project name (e.g., MyMauiAndroidApp) and a location. Click Next.
5. On the Additional information screen, ensure the .NET target framework is set to .NET 6.0 (or later). Click Create.

Visual Studio will create a new .NET MAUI project with sample code.

Understanding the Project Structure

Key folders for Android development include:

• Platforms/Android: Contains Android-specific resources and manifest files.
• Resources/Drawable: For Android drawable resources (icons, images).
• Resources/Values: For Android string and color resources.

Running on an Android Emulator

Now, let's deploy our application to the emulator.

1. Ensure your Android emulator is running from the Android Device Manager.
2. In the Visual Studio toolbar, locate the debug target dropdown. Select your running Android emulator from the list.
3. Click the Local Windows Debugger button (the green play icon) or press F5 to build and deploy the application to the emulator.

The application will build, deploy, and launch on your selected Android emulator. You should see the default MAUI template application.

Exploring Android-Specific Features

While .NET MAUI aims for code sharing, you can still leverage Android-specific APIs when needed.

To access Android-specific functionality, you can use conditional compilation or platform-specific implementations.

Accessing Android APIs

You can use the Microsoft.Maui.ApplicationModel namespace and check the platform.

#if ANDROID
using Android.App;
using Android.Widget;
#endif

// ... in a method or event handler ...

#if ANDROID
    // Access Android specific features
    Toast.MakeText(Android.App.Application.Context, "Hello from Android!", ToastLength.Short).Show();
#endif
            

You can also define platform-specific code within the Platforms/Android folder for specific handlers or implementations.

Debugging and Troubleshooting

Visual Studio provides powerful debugging tools for .NET MAUI Android applications.

• Breakpoints: Set breakpoints in your C# code to inspect variables and step through execution.
• Output Window: Monitor build logs, deployment messages, and device output.
• Android Device Manager: View device logs, capture screenshots, and manage emulators.

Common Issues and Solutions:

Next Steps

Congratulations on getting your first .NET MAUI app running on Android! Here are some suggestions for continuing your learning journey:

• Explore more advanced UI layouts and controls.
• Learn about data binding and MVVM pattern for structured application development.
• Integrate device features like camera, GPS, and sensors.
• Investigate platform-specific customizations for Android.
• Test your application on physical Android devices.

Continue to refer to the official .NET MAUI documentation for comprehensive guides and API references.