MAUI Bluetooth Permission Declaration (for Android)

BluetoothPermissions.Android.cs

// IMPORTANT: Put this file in `Platforms/Android/` directory.
using Microsoft.Maui.ApplicationModel;
using System.Collections.Generic;

/// <summary>
///		MAUI Bluetooth Permission Decleration (for Android).
/// </summary>
/// <remarks>
///		IMPORTANT: Put this file in `Platforms/Android/` directory.
/// </remarks>
public partial class BluetoothPermissions : Permissions.BasePlatformPermission
{
	private readonly bool _scan;
	private readonly bool _advertise;
	private readonly bool _connect;
	private readonly bool _bluetoothLocation;

	public BluetoothPermissions()
		: this(true, false, true, false)
	{
	}

	/// <summary>
	/// 
	/// </summary>
	/// <param name="scan">Needed only if your app looks for Bluetooth devices.
	/// If your app doesn't use Bluetooth scan results to derive physical location, you can make a strong assertion that your app never uses the Bluetooth permissions to derive physical location. 
	/// Add the `android:usesPermissionFlags` attribute to your BLUETOOTH_SCAN permission declaration, and set this attribute's value to `neverForLocation`.
	/// </param>
	/// <param name="advertise">Needed only if your app makes the device discoverable to Bluetooth devices.</param>
	/// <param name="connect">Needed only if your app communicates with already-paired Bluetooth devices.</param>
	/// <param name="bluetoothLocation">Needed only if your app uses Bluetooth scan results to derive physical location.</param>
	/// <remarks>
	///  https://developer.android.com/guide/topics/connectivity/bluetooth/permissions
	/// </remarks>
	public BluetoothPermissions(bool scan = true, bool advertise = true, bool connect = true, bool bluetoothLocation = true)
	{
		_scan = scan;
		_advertise = advertise;
		_connect = connect;
		_bluetoothLocation = bluetoothLocation;
	}

	private (string androidPermission, bool isRuntime)[] _requiredPermissions;

	public override (string androidPermission, bool isRuntime)[] RequiredPermissions
	{
		get
		{
			if (_requiredPermissions != null)
				return _requiredPermissions;

			var result = new List<(string androidPermission, bool isRuntime)>();

			var sdk = (int)Android.OS.Build.VERSION.SdkInt;
			if (sdk >= 31)
			{
				// If your app targets Android 12 (API level 31) or higher, declare the following permissions in your app's manifest file:

				if (_scan)
					result.Add((global::Android.Manifest.Permission.BluetoothScan, true));

				if (_advertise)
					result.Add((global::Android.Manifest.Permission.BluetoothAdvertise, true));

				if (_connect)
					result.Add((global::Android.Manifest.Permission.BluetoothConnect, true));

				if (_bluetoothLocation)
					result.Add((global::Android.Manifest.Permission.AccessFineLocation, true));
			}
			else
			{
				// If your app targets Android 11 (API level 30) or lower, declare the following permissions in your app's manifest file:

				result.Add((global::Android.Manifest.Permission.Bluetooth, true));

				if (sdk >= 29)
				{
					result.Add((global::Android.Manifest.Permission.AccessFineLocation, true));
				}
				else
				{
					// If your app targets Android 9 (API level 28) or lower, you can declare the ACCESS_COARSE_LOCATION permission instead of the ACCESS_FINE_LOCATION permission.

					result.Add((global::Android.Manifest.Permission.AccessCoarseLocation, true));
				}

				if (_scan || _connect || _advertise)
				{
					result.Add((global::Android.Manifest.Permission.BluetoothAdmin, true));

					if (sdk >= 29)
					{
						// If your app supports a service and can run on Android 10 (API level 29) or Android 11, you must also declare the ACCESS_BACKGROUND_LOCATION permission to discover Bluetooth devices. 

						result.Add((global::Android.Manifest.Permission.AccessBackgroundLocation, true));
					}
				}
			}
			_requiredPermissions = result.ToArray();

			return _requiredPermissions;
		}
	}
}

BluetoothPermissions.cs

	/// <summary>
	/// IMPORTANT: Put this file in root of Application
	/// </summary>
	public partial class BluetoothPermissions : Permissions.BasePlatformPermission
	{
	}

BluetoothPermissions.Helper.cs

// How to use MAUI Bluetooth LE permissions

private async Task<bool> CheckBluetoothStatus()
{
	try
	{
		var requestStatus = await new BluetoothPermissions().CheckStatusAsync();
		return requestStatus == PermissionStatus.Granted;
	}
	catch (Exception ex)
	{
		// logger.LogError(ex);
		return false;
	}
}

public async Task<bool> RequestBluetoothAccess()
{
	try
	{
		var requestStatus = await new BluetoothPermissions().RequestAsync();
		return requestStatus == PermissionStatus.Granted;
	}
	catch (Exception ex)
	{
		// logger.LogError(ex);
		return false;
	}
}

Hello and thank you for this code. However, I don't understand the purpose of the BluetoothPermissions class at the root of Application. How do you make the link between BluetoothPermissions at the root of Application and BluetoothPermissions in Platforms.Android ? I have the impression that my programme doesn't pass into BluetoothPermissions in Plateforms.Android...

Ok, I Find answer here : https://learn.microsoft.com/en-us/dotnet/maui/platform-integration/invoke-platform-code?view=net-maui-8.0#partial-classes-and-methods