Using Microsoft.Azure.Devices.Client in Xamarin.Forms Android project

[damir-bajramovic]

I made a Xamarin.Forms project. .NET Standard is the code sharing strategy. Using Visual Studio, Windows 10.

I am able to send messages to the IoT Hub on the UWP app, but not from Android. Build succeeds, but it doesn't deploy right on the device.

Description of the issue:

I installed 1.7.0 version of Microsoft.Azure.Devices.Client NuGet package.

Code sample exhibiting the issue:

public class IoT
{
    public IoT(string connectionString)
    {
        _deviceClient = DeviceClient.CreateFromConnectionString(connectionString, TransportType.Http1);
    }
    private DeviceClient _deviceClient;

    public async Task SendMessage(object data)
    {
        try
        {
            Message message = new Message(Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(data)));
            if (_deviceClient != null)
            {
                await _deviceClient.SendEventAsync(message);
            }
            else Debug.WriteLine("Message failed to send" + JsonConvert.SerializeObject(data));
        }
        catch
        {
            Debug.WriteLine("EXCEPTION!");
        }
    }
}

}

These are some of the entries when I build the project:

Ignoring C:\Users\User.nuget\packages\system.runtime.compilerservices.unsafe\4.4.0\ref

And after the deployment fails I see this:

03-29 09:59:37.727 D/Mono (24241): Assembly Loader probing location: 'System.Runtime.CompilerServices.Unsafe'.
03-29 09:59:37.727 F/monodroid-assembly(24241): Could not load assembly 'System.Runtime.CompilerServices.Unsafe' during startup registration.
03-29 09:59:37.727 F/monodroid-assembly(24241): This might be due to an invalid debug installation.
03-29 09:59:37.727 F/monodroid-assembly(24241): A common cause is to 'adb install' the app directly instead of doing from the IDE.

How to resolve this issue? Is it even possible to use Microsoft.Azure.Devices.Client for Android devices?

I tried various linker options but to no avail.

Issue sample repo

Check out the repo with the sample code: https://github.com/ChakraSpice/Xamarin-IoT-Android-Issue-Sample (use your own connection string)

[craylward]

This is a known Xamarin.Android issue: dotnet/android#1162

Also listed as an issue in this repo: #373

Try replacing the contents of
USER\.nuget\packages\system.runtime.compilerservices.unsafe\4.4.0\ref with contents of USER\.nuget\packages\system.runtime.compilerservices.unsafe\4.4.0\lib

[damir-bajramovic]

I tried that, and that doesn't work.

[CIPop]

Thanks @craylward and @ChakraSpice . We are aware of several Xamarin issues and we will need to spend more time investigating.

[abhipsaMisra]

We have updated some Xamarin Android samples in our repository which implement send & receive messages. Could you please try with those and let us know if it helps! Thanks!

[abhipsaMisra]

@ChakraSpice - Could you please try out using the latest samples and let us know if that helps. In case you face further issues, please open another GitHub issue. Thanks!

[nimanasr]

I have the same issue when trying to deploy the application on Android emulator. I tried your samples but I get the old error message. Which sample do you exactly mean?

[abhipsaMisra]

@nimanasr - The Xamarin Android issue which was causing this error has since been resolved. Please make sure that you have the latest versions of the entire tool-chain installed; and you can refer to the samples present here. Please let us know if that helps. Thanks!

[nimanasr]

@abhipsaMisra the issue is resolved after upgrading Visual Studio 2017 to version 15.7.5. Thanks!