xamarin/xamarin-android

Development discussion of Xamarin.Android: https://github.com/xamarin/xamarin-android

Jonathan Pobst

@jpobst

unfortunately not, it generally happens trying to resolve a generic constraint

you can try setting the Android Class Parser to jar2xml as a workaround, it should avoid this crash, but it may fail elsewhere

Aimoré Sá Costa

@aimore

Yeah I have done it already
but still the other problem with the 2k + syntax errors and don't know if I need to change it manually for every method

in the MetaData.xml

Jonathan Peppers

@jonathanpeppers

@knocte I was able to build Xamarin.Android projects with Github actions here: https://github.com/jonathanpeppers/boots/blob/master/.github/workflows/actions.yml
I would recommend building on mac if you want to use boots, it's faster to install a pkg than a vsix
that build step only took 2 min, even though it downloads/installs .NET Core, Mono, & Xamarin.Android

Andres G. Aragoneses

@knocte

@jonathanpeppers yeah thanks, after this commit (nblockchain/ZXing.Net.Xamarin@243c963), it's past that error

@jonathanpeppers so you could answer this SO (I'll upvote): https://stackoverflow.com/questions/58065468/xamarin-android-support-with-githubactions-workflows-or-how-to-install-jdk-pro

Jonathan Peppers

@jonathanpeppers

:thumbsup: https://stackoverflow.com/a/58122303/132442

Andres G. Aragoneses

@knocte

@jonathanpeppers you said the env var thing is fixed in 16.3? interestingly enough, XF folks seem to have the bug precisely in this version: xamarin/Xamarin.Forms#7707

Jonathan Peppers

@jonathanpeppers

The image they have would still be 16.2: Hosted Windows 2019 with VS2019

I don’t see anything provisioning Xamarin.Android yet, maybe just a typo

I know I have been able to remove that workaround from all my OSS projects after using 16.3 and boots

Tomasz Cielecki

@Cheesebaron

We have a Samsung Galaxy S6 in the office that crashes with a SIGSEGV 11: https://gist.github.com/Cheesebaron/b12e44cc12d1e2c8f7810ee92c4cc8de#file-gistfile1-txt I have no idea what is going on. It reminds me of that issue there was with the debugging on arm64 not too long ago

Only seems to crash on this device, which happens when finishing one Activity going back to the "root"

Tomasz Cielecki

@Cheesebaron

Tried 10 other devices they don't show this behavior. Only the SGS6

juepiezhongren

@juepiezhongren

@jonathanpeppers when will android support c#8？

Jonathan Pryor

@jonpryor

@juepiezhongren: what do you mean by "support"? Which features are you interested in?

Jonathan Pryor

@jonpryor

@juepiezhongren: AFAIK, XA 10.0/VS 16.3 should support nullable reference types, the new System.Index and System.Range types, and C# interface default members. BUT, while you can compile code using interface default members, XA 10.0 has a bug in which those are replaced at packaging time, breaking things. That issue is fixed in the XA10.0.99/VS 16.4 P1, which also introduces support for binding Java 8 interface default methods as C#8 default interface members: https://docs.microsoft.com/en-us/xamarin/android/release-notes/10/10.1#binding-project-improvements-with-c-80-for-java-interface-members

juepiezhongren

@juepiezhongren

thx

juepiezhongren

@juepiezhongren

i found async stream not supported

Jonathan Pobst

@jpobst

what does it do? does it give you an exception?

Atsushi Eno

@atsushieno

Anyone here interested in giving a talk about Xamarin in Tokyo, at https://droidkaigi.jp/2020/en/ ? They pay for trip this year.

(I'm not involved or affiliated, just thought it might be fun for some ppl.)

Sébastien Goyette

@crogeniks

Was there any changes recently about how Xamarin's HttpClient handles HttpContent?
Before updating to 16.3, I was able to read the HttpContent of HttpResponseMessage.RequestMessage.Content. After updating, it now throws a ObjectDisposedException exception

Jonathan Pryor

@jonpryor

@brendanzagaeski? ^^

@crogeniks: I’m aware of some changes in HttpClient, but nothing about that.

Sébastien Goyette

@crogeniks

The HttpContent itself doesn't seems to be disposed however, which is even more weird (_disposed = false in HttpContent)

Jonathan Pryor

@jonpryor

what’s the stack trace of the ObjectDisposedException?

Sébastien Goyette

@crogeniks

     0xD in System.IO.MemoryStream.EnsureNotClosed    C#
     0x1 in System.IO.MemoryStream.get_Length    C#
     0x6 in System.Net.Http.HttpContent.ReadBufferedContentAsString    C#
     0x1 in System.Net.Http.HttpContent.<>c.<ReadAsStringAsync>b__36_0    C#
     0x77 in System.Net.Http.HttpContent.<WaitAndReturnAsync>d__67<System.Net.Http.WaitAndReturnAsync    C#
     0x33 in System.Runtime.CompilerServices.AsyncTaskMethodBuilder<string>.Start<System.Net.Http.HttpContent.<WaitAndReturnAsync>d__67<System.Net.Http.HttpContent,string>>    C#
     0x37 in System.Net.Http.HttpContent.WaitAndReturnAsync<System.Net.Http.HttpContent, string>    C#
     0x2C in System.Net.Http.HttpContent.ReadAsStringAsync    C#

Jonathan Pryor

@jonpryor

and that partially explains something: there’s a MemoryStream involved, and the MemoryStream has been disposed.

@lambdageek? ^^ :smile:

Sébastien Goyette

@crogeniks

ah right. HttpContent's _bufferedContent is indeed disposed

Jonathan Pryor

@jonpryor

which raises the next question, why is _bufferedContent disposed?

Sébastien Goyette

@crogeniks

As context : I am calling await System.Net.Http.HttpClientExtensions.PostAsJsonAsync<T>(this HttpClient client, string requestUri, T value, CancellationToken cancellationToken)

This gives me a HttpResponseMessage that I'm accessing right after that await, and I get the exception

Jonathan Pryor

@jonpryor

what’s odd is i only see one _bufferedContent.Dispose() call, and that’s in HttpContent.Dispose()

which is called after _disposed=true

so i don’t statically see why you’d be seeing that state.

Sébastien Goyette

@crogeniks

going to test in VS2017 after it updates, see if I get the same issue

Sébastien Goyette

@crogeniks

I confirm that VS2017 doesn't have the issue

Sébastien Goyette

@crogeniks

the variable names changed between 2017 and 2019, but I don't find them in github
https://github.com/mono/mono/tree/master/mcs/class/System.Net.Http/System.Net.Http is the right place to see the sources?

Jonathan Pryor

@jonpryor

@crogeniks: not entirely. Much of HttpClient is from corefx now: https://github.com/dotnet/corefx/tree/master/src/System.Net.Http/src/System/Net/Http

Sébastien Goyette

@crogeniks

@jonpryor ah! I do not get this exception if I avoid the PostAsJsonAsync extensions!

I see! thanks for that info

Brendan Zagaeski

@brendanzagaeski

Out of curiosity from https://github.com/xamarin/xamarin-android/issues/3513#issuecomment-534886271, since I don't recall off-hand what the story was with the Linux CI builds, I'm guessing the goal is to reenable those eventually, but at the moment they're disabled awaiting a moment where there's time to investigate why they were failing?