MAUI Binding .aar library

[vfongmala]

I tried to adapt the approach from https://docs.microsoft.com/en-us/xamarin/android/platform/binding-java-library/binding-an-aar into my MAUI project.
But I have not succeeded so far. I cannot reference the binding project into the main project.
Any suggestion on how can I use native library in MAUI project?

[realZhangChi]

In .net6.0, there is a new project template Android Java Library Binding (android-bindinglib), you can use it to create your binding library. However, the binding library of xamarin can also be used in maui, so I think maybe you encountered a problem when creating the binding library.

[realZhangChi]

I'm also trying to create a binding library, but I'm having problems, this is the relevant issue. do you know how to solve this problem? Thanks.

[AdamDiament]

Hi @realZhangChi -
re

However, the binding library of xamarin can also be used in maui

This sounds great! Is this documented anywhere?

[ksivasenthil]

However, the binding library of xamarin can also be used in maui, so I think maybe you encountered a problem when creating the binding library.

This might not be entirely true. Though the official document (@AdamDiament I was also searching for this!) MAUI migration guide for binding libraries calims the following -

In .NET 6+, there is no longer a concept of a binding project as a separate project type. Any of the MSBuild item groups or build actions that currently work in binding projects will be supported through a .NET 6+ Android application or library.

Despite that we were having trouble making a Android Bindings Library (Xamarin) compile in Azure DevOps CI pipeline environment post MAUI migration for the app that consumed the Android Binding Library (Xamarin).

We could not get past the step _AndroidAotCompilation target with relevant error message being the following

error : Mono: Request to load PdfViewerX in alc 000001F7A9848DB0 [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error : Mono: The following assembly referenced from D:\a\1\s\---\---\obj\Release\net7.0-android\android-x64\linked\Core.dll could not be loaded: [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error :      Assembly:   PdfViewerX    (assemblyref_index=21) [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error :      Version:    1.0.0.0 [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error : Mono: Failed to load assembly Core[000001F7A9845EC0]. [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error : Failed to load method 0x60002b0 from 'D:\a\1\s\---\---\obj\Release\net7.0-android\android-x64\linked\Core.dll' due to Could not load file or assembly 'PdfViewerX, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies.. [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]
error : AOT of image obj\Release\net7.0-android\android-x64\linked\Core.dll failed. [D:\a\1\s\---\---\---.csproj::TargetFramework=net7.0-android]

Needless to say, many steps above this the PdfViewerX was built successfully and the binding project has the aar embedded inside the PdfViewerX.dll using the LibraryProjectZip build action.

Please let me know if we are doing something silly but we are going to try by switching to the SDK style project available from the MAUI Android Java Library Binding.

[rkops-bd]

I don't have the buildaction LibraryProjectZip when trying to create a binding for an .aar file in VS2022 Preview

[Kebechet]

use AndroidLibrary instead

[yushulx]

In Visual Studio 2022 preview, create an Android Java Library Binding project.

Then click the aar file and change the build action to AndroidLibrary

Here is my project: https://github.com/yushulx/barcode-dotnet-mobile/tree/main/android

[rbprakash]

i',m trying to Binding an .arr file by following above mentioned steps. getting these kind of errors, can some one help ?

Severity Code Description Project File Line Suppression State
Error CS1001 Identifier expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1513 } expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1514 { expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 10 Active
Error CS1026 ) expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 11 Active
Error CS1031 Type expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 11 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 11 Active
Error CS1002 ; expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 11 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 11 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 35 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 35 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 35 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 35 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 35 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 36 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS8803 Top-level statements must precede namespace and type declarations. AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1525 Invalid expression term 'int' AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1002 ; expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1026 ) expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1002 ; expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 41 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 58 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C:\MAUI\AndroidBinding1\obj\Debug 59 Active
Error CS1001 Identifier expected AndroidBinding1 C: 10 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C: 10 Active
Error CS1513 } expected AndroidBinding1 C: 10 Active
Error CS1514 { expected AndroidBinding1 C: 10 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 10 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C: 10 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 10 Active
Error CS1026 ) expected AndroidBinding1 C: 11 Active
Error CS1031 Type expected AndroidBinding1 C: 11 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C: 11 Active
Error CS1002 ; expected AndroidBinding1 C: 11 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 11 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C: 35 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C: 35 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C: 35 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 35 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C: 35 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 36 Active
Error CS0116 A namespace cannot directly contain members such as fields, methods or statements AndroidBinding1 C: 41 Active
Error CS1056 Unexpected character 'Ɪ' AndroidBinding1 C: 41 Active
Error CS8803 Top-level statements must precede namespace and type declarations. AndroidBinding1 C: 41 Active
Error CS1525 Invalid expression term ')' AndroidBinding1 C: 41 Active
Error CS1002 ; expected AndroidBinding1 C: 41 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 41 Active
Error CS1002 ; expected AndroidBinding1 C: 41 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 58 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 70 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 82 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 95 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 107 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 122 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 134 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 149 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 161 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 173 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 186 Active
Error CS0106 The modifier 'public' is not valid for this item AndroidBinding1 C: 201 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 212 Active
Error CS1022 Type or namespace definition, or end-of-file expected AndroidBinding1 C: 213 Active

[MhAllan]

If you learn Kotlin and Swift you will finish your app before the binding is fixed, if it ever gets fixed.

[bbhxwl]

I don't know how to bind an aar, can you help me?

[MhAllan]

no good tools and endless effort, good luck

[caoyiliang]

Thank you for your letter, I will reply as soon as possible