When using BLE, warning is output in release build

[usausa]

Android framework version

net10.0-android (Preview)

Affected platform version

VS 2026

Description

When you add a library that uses BLE and run a Release build, the following warning is displayed.

11:13 で再構築が開始されました...
1>------ すべてのリビルド開始: プロジェクト:MauiApp1, 構成: Release Any CPU ------
D:\Workspace\MauiApp1\MauiApp1\MauiApp1.csproj を復元しました (103 ミリ秒)。
1>  MauiApp1 -> D:\Workspace\MauiApp1\MauiApp1\bin\Release\net10.0-android\MauiApp1.dll
1>  アセンブリのサイズを最適化すると、アプリの動作が変わる可能性があります。公開した後に必ずテストしてください。https://aka.ms/dotnet-illink を参照してください
1>  アセンブリのサイズを最適化しています。このプロセスには時間がかかる場合があります。
1>  アセンブリのサイズを最適化すると、アプリの動作が変わる可能性があります。公開した後に必ずテストしてください。https://aka.ms/dotnet-illink を参照してください
1>  アセンブリのサイズを最適化しています。このプロセスには時間がかかる場合があります。
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1498,3): warning : Connector name 'GetOnServiceAdded_ILandroid_bluetooth_BluetoothGattService_Handler_ext' must start with 'Get', end with 'Handler' and have at least one character between the two parts.
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1498,3): warning : Method 'System.Void Android.Bluetooth.BluetoothGattServerCallback::OnServiceAdded(Android.Bluetooth.ProfileState,Android.Bluetooth.BluetoothGattService)' will be registered dynamically [Arch: None; Assembly: unknown]
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1498,3): warning : Connector name 'GetOnServiceAdded_ILandroid_bluetooth_BluetoothGattService_Handler_ext' must start with 'Get', end with 'Handler' and have at least one character between the two parts.
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1498,3): warning : Method 'System.Void Android.Bluetooth.BluetoothGattServerCallback::OnServiceAdded(Android.Bluetooth.ProfileState,Android.Bluetooth.BluetoothGattService)' will be registered dynamically [Arch: None; Assembly: unknown]
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1585,3): warning : Connector name 'GetOnServiceAdded_ILandroid_bluetooth_BluetoothGattService_Handler_ext' must start with 'Get', end with 'Handler' and have at least one character between the two parts.
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1585,3): warning : Method 'System.Void Android.Bluetooth.BluetoothGattServerCallback::OnServiceAdded(Android.Bluetooth.ProfileState,Android.Bluetooth.BluetoothGattService)' will be registered dynamically [Arch: None; Assembly: obj\Release\net10.0-android\android-x64\linked\Mono.Android.dll]
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1585,3): warning : Connector name 'GetOnServiceAdded_ILandroid_bluetooth_BluetoothGattService_Handler_ext' must start with 'Get', end with 'Handler' and have at least one character between the two parts.
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1585,3): warning : Method 'System.Void Android.Bluetooth.BluetoothGattServerCallback::OnServiceAdded(Android.Bluetooth.ProfileState,Android.Bluetooth.BluetoothGattService)' will be registered dynamically [Arch: None; Assembly: obj\Release\net10.0-android\android-arm64\linked\Mono.Android.dll]
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1603,3): warning : [Arm64] Number of methods in the project that will be registered dynamically: 1
1>C:\Program Files\dotnet\packs\Microsoft.Android.Sdk.Windows\36.1.2\tools\Xamarin.Android.Common.targets(1603,3): warning : [X86_64] Number of methods in the project that will be registered dynamically: 1
1>  [1/98] _Microsoft.Android.Resource.Designer.dll -> _Microsoft.Android.Resource.Designer.dll.so
...

Steps to Reproduce

1. Create a MAUI project.
2. Select net10.0-android as the Target Framework.
3. Add the library that uses Bluetooth.

	<ItemGroup>
		<PackageReference Include="Shiny.BluetoothLE" Version="3.3.4" />
		<PackageReference Include="Shiny.BluetoothLE.Hosting" Version="3.3.4" />
		<PackageReference Include="Shiny.Hosting.Maui" Version="3.3.4" />
	</ItemGroup>

4. Run a release build

Did you find any workaround?

No response

Relevant log output

[jonathanpeppers]

This looks like the warning is related to marshal methods:

android/src/Xamarin.Android.Build.Tasks/Utilities/MarshalMethodsClassifier.cs

Lines 744 to 750 in 29f8376

	string connectorName = connector.MethodName;
	if (connectorName.Length < HandlerNameStart.Length + HandlerNameEnd.Length + 1 ||
	!connectorName.StartsWith (HandlerNameStart, StringComparison.Ordinal) ||
	!connectorName.EndsWith (HandlerNameEnd, StringComparison.Ordinal)) {
	log.LogWarning ($"Connector name '{connectorName}' must start with '{HandlerNameStart}', end with '{HandlerNameEnd}' and have at least one character between the two parts.");
	return false;
	}

But it's warning about methods in Mono.Android.dll?

/cc @grendello