We have a couple of ELO touch tablets and status lights and a jar file ("eloperipherallib.jar") to change the color of the status light. Though we are not Java developers, we were able to create an .apk (with Android Studio) and change the color of the status light using this jar.
We now want to do the same in .NET, using Xamarin. We therefore created an "Android Bindings Library (Xamarin)" and added the jar (following the instructions here: https://learn.microsoft.com/en-us/xamarin/android/platform/binding-java-library/binding-a-jar). When building the bindings library we get the following warnings:
warning BG8605: The Java type 'android.elo.peripheral.ELOPeripheralEventListener' could not be found (are you missing a Java reference jar/aar or a Java binding library NuGet?)
warning BG8605: The Java type 'android.elo.peripheral.ELOPeripheralManager' could not be found (are you missing a Java reference jar/aar or a Java binding library NuGet?)
warning BG8606: Some types or members could not be bound because referenced Java types could not be found. See the 'java-resolution-report.log' file for details.
And at runtime we get a similar exception when "ELOPeripheralManager" is used.
Now, we do not have this problem in the .apk created with Android Studio, so I guess the jar file contains everything that is needed. We just can't figure out what the Xamarin project is missing, if that what's missing is in the jar file anywhere and/or how we can get it out of the jar file and put it in the Xamarin project so it'll build…
Can someone point us in the right direction?
Related
I am trying to build Xamarin Android binding libraries for two different RFID hand held scanner SDKs (from two different companies), and then reference them in a Xamarin.Android project. So the end goal is to have one application that can run on Device A or Device B and depending on the device manufacturer it will use a different implementation of a "scanner" interface. If I try to reference both of the resulting dlls from the Xamarin.Android project, then I get the following error:
Program type already present: com.hsm.barcode.DecodeOptions
Looking in the jars using JD-GUI as suggested in the Microsoft Docs I can see the problem is that both of the jars have a com.hsm.barcode package:
What is the best way to workaround this issue?
Note that if I use only one of the dlls then I have no issues.
What I have tried:
Using a single Xamarin Android binding library project for both jars - this gave exactly the same result
Renaming all of the classes in the jar to eliminate duplicate class names like this: <attr path="/api/package[#name='com.hsm.barcode']/class[#name='DecodeOptions']" name="name">DecodeOptions2</attr>. When I do this, in reflector I can see that the class name has indeed changed, but I still get the build error when building the Xamarin.Android project
Renaming the namespace in one of the projects: <attr path="/api/package[#name='com.hsm.barcode']" name="name">com.hsm.barcode2</attr>. Again, I can see the updated namespace in reflector but still I get the same "Program type already present" error when building the Xamarin.Android project
Similarly I have tried removing both the namespace and the duplicate classes using remove-node but seen similar results
This leads me to believe that this isn't necessarily an issue with the binding process but rather a more Android related problem. I have found some similar Android questions where people mention that you can use exclude module in gradle to remove dependencies [1] [2], but a) there seems to be no concrete answer that this is the right approach in this case and b) as I have been able to find gradle is not a tool that is used as part of the Xamarin/Visual Studio process.
My final desperate attempt to get something working was to unzip one of the jar files, remove all the .class files that are causing issues, then rezip and use this in the Android binding library and then reference this dll in my Xamarin.Android project. This seems to work (the project builds and runs) but I'm not sure it is the correct/safest/most stable solution.
To summarize, the question is: if you have two jars with duplicated namespaces/packages and you want to use both of these Jars in a Xamarin.Android project how can you avoid the resulting Program type already present: com.hsm.barcode.DecodeOptions error message.
I am trying to use https://github.com/Redth/Xamarin.Android.Xposed in Xamarin but the final result is rejected by Xposed, saying: "cannot load module" .. "the xposed api classes are compiled into the module's apk". The xposed-api.jar file is currently a EmbeddedJar, which is what causes that error. The xposed-api.jar file is made available during run-time by Xposed already.
From the xamarin docs.
InputJar – Does not embed the .jar into the resulting Bindings Library .DLL. Your Bindings Library .DLL will have a dependency on this .jar at runtime.
InputJar seems like it will solve my issue with it being compiled into the resulting apk. However, it can't compile into an apk at all. It gives me errors in the generated java file such as.
JAVAC0000: error: package de.robv.android.xposed does not exist
de.robv.android.xposed.IXposedHookLoadPackage 0
Then for ReferenceJar..
ReferenceJar – Specifies a reference .jar: a reference .jar is a .jar that one of your bound .jar or .AAR files depends on. This reference .jar is used only to satisfy compile-time dependencies. When you use this build action, C# bindings are not created for the reference .jar and it is not embedded in the resulting Bindings Library .DLL.
Great, it will provide it during compile-time.. however, no bindings will be generated so I can't use it.
I also tried combining these by creating 2 identical libraries with one having InputJar and the other ReferenceJar, but that did not work at all.
How can I achieve what I am trying to do?
To sum it up, I need to add xposed-api.jar as a library just like how android.jar of the Android framework is added. You can use the classes and compile properly, without the classes being compiled into the apk.
OK, The trick is actually "AndroidExternalJavaLibrary".
Imagine you have a Jar binding project XPosedAPI, and an Android project XposedSample.
The structure would be:
XPosedAPI
|-- Jar
|-- api-82.jar (InputJar)
XposedSample
|-- Jar
|-- api-82.jar (AndroidExternalJavaLibrary)
You see, the trick is you have to put the same jar file for each project.
For the Jar binding project, it has to be "InputJar" - that's used to generate the C# binding dll.
For the project that using the Jar bindng dll, the jar has to be "AndroidExternalJavaLibrary". This ensures the javac compile process.
There was an easier way, the Java.Interop.DoNotPackageAttribute.
You just put the below line on one of these projects (just put it on XPosedAPI project would be enough), and it works:
[assembly: Java.Interop.DoNotPackage("api-82.jar")]
However, this attribute is marked as "deprecated", although it's easier.
I figured out this, because I'm trying to do the same thing - write a xposed module in C#.
The Xamarin.Android.Xposed project looks nice, but in fact it won't work, and there are much more problems to be fixed besides the jar binding issue.
I think I'm getting closer, and I may publish it in a few days if I can fix all the bugs remained.
If you're interested, watch my project: https://github.com/UlyssesWu/XamarinPosed
Summary
When binding a JAR/AAR built on top of aws-java-sdk, do you have to EmbeddedReferenceJar all the libraries below your JAR, down to and including the aws-java-sdk, when down at that low level the AWS SDK for .NET has the functionality.
Are there any Xamarin packages (Xamarin.Forms or Xamarin.Android) that give an out-of-the box authentication UI with Sign-In/Sign-Up buttons for AWS user pools, Google+, Facebook authentication providers ?
Context
I would like to use SignInUI from aws-android-sdk-auth-ui in a Xamarin.Android app, which gives you an out-of-the-box UI for authentication to AWS. I've got the AWS UserPool and AWS IdentityPool setup already.
Unfortunately, the AWS SDK for .NET does not expose the equivalent aws-android-sdk-auth-ui a java package built on top of aws-android-sdk-auth-core (also unavailable in .NET), which is built on top of aws-android-sdk-core and finally aws-java-sdk.
I thought about binding a java library. I would create a Xamarin binding project for aws-android-sdk-auth-ui.aar downloaded from maven Central. I followed the Binding an .AAR tutorial. It builds, but the generated aws-android-sdk-auth-ui.dll file is missing some classes. I opened the dll with Ildasm.exe and in the Com.Amazonaws.Mobile.Auth.UI namespace I only found AuthUIConfiguration and BuildConfig, clearly missing the SignInUI class.
Is it expected that when you build a binding project for an .aar file that references other .jar, the build succeeds but silently does not produce wrapper classes for java classes who reference missing jars? I would have guessed building would succeed AND would include a wrapper for all classes, but a failure would occur at runtime in codepaths that require the missing jar.
Alright, so I added aws-android-sdk-auth-core.jar, aws-android-sdk-core.jar to the bindings project, as EmbeddedReferencedJar. That did not help, the generated dll is also missing the same classes. The build output pasted below does point in the direction of misssing reference jars. See below.
How far do I need to go though, do I also need to embed all the way down to the 80MB aws-java-sdk.jar?
I have the following build output:
1>JARTOXML : warning J2X9001: Couldn't load class com/amazonaws/mobile/auth/ui/SignInActivity : java.lang.NoClassDefFoundError: android/support/v7/app/AppCompatActivity
1>JARTOXML : warning J2X9001: Couldn't load class com/amazonaws/mobile/auth/ui/SignInUI$1 : java.lang.NoClassDefFoundError: com/amazonaws/mobile/auth/core/DefaultSignInResultHandler
1>JARTOXML : warning J2X9001: Couldn't load class com/amazonaws/mobile/auth/ui/SignInActivity$SignInProviderResultHandlerImpl : java.lang.NoClassDefFoundError: com/amazonaws/mobile/auth/core/signin/SignInProviderResultHandler
android/support/v7/app/AppCompatActivity indicates that com.android.support:appcompat isn't found. How are those supposed to bind? In Xamarin.Android these classes are in
Xamarin.Android.Support.v7.AppCompat Nuget package. But the jar does not know it's running in Xamarin.Android. Does that mean I also need to EmbedReferenceJar all the native Android stuff as well? That's a deep rabbit hole...
com/amazonaws/mobile/auth/core/DefaultSignInResultHandler: that one should not error, I did embed aws-android-sdk-auth-core.jar with EmbbededRefenceJar
Update:
Someone referred me to Xamarin.GradleBindings. I haven't tested this yet, but thought I'd share in hopes this can be useful to other readers.
I'm using Xamarin forms to build an app that prints some content with a citizen printer.
In order to do so I downloaded the printer jar and created a Bindings Library to use the jar in my project.
But I get this warning BINDINGSGENERATOR : warning BG8102: Class Com.Citizen.Sdk.ESCPOSPrinter has unknown base type com.citizen.csjposlib.c.c.
And I'm not hable to access the classes I need.
How can I solve this?
Using the google play games services and Admob plugin I cannot seem to get my back to build into an APK and I am receiving the following error message. Any help would be appreciated as I have removed some duplicate files but I am still failing to find why I cannot build my app.
I am using Unity Unity 5.6.1f1 (64-bit).
game services: https://github.com/playgameservices/play-games-plugin-for-unity Ads: https://github.com/unity-plugins/Firebase-Admob-Unity
CommandInvokationFailure: Unable to convert classes into dex format.
C:/Program Files/Java/jdk1.8.0_121\bin\java.exe -Xmx2048M -Dcom.android.sdkmanager.toolsdir="C:/Users/Jack/AppData/Local/Android/sdk\tools" -Dfile.encoding=UTF8 -jar "C:\Program Files\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar" -
stderr[
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzbyb;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzbyc;
2 errors; aborting
]
Some Background
When Unity builds your project for Android, it invokes several tools from the Android SDK. As part of that process, it converts all of your native (Java) code for Android into a file format called DEX (Dalvik executable).
All of your Android plugins get built up into a single package using that tool. The problems start when a few plugins have the same compiled Java code (classes) in them. This will cause the DEX tool to fail with an error like the one you're seeing:
Uncaught translation error: java.lang.IllegalArgumentException:
already added: Lcom/google/android/gms/internal/zzbyb;
Uncaught translation error: java.lang.IllegalArgumentException: already added: Lcom/google/android/gms/internal/zzbyc;
This means that classes with those names were already included in another library, and so they cannot be added again.
Possible Causes
As explained above, this error occurs when you have duplicate plugins in your project; this can happen in different scenarios, here are some examples:
The same plugin is included more than once, under different folders of the project.
The same plugin is included more than once with different versions.
A plugin contains other dependencies "embedded" inside it, but these dependencies are already included in the project in some form.
How To Fix
You should look up duplicate Android plugins in your project and eliminate them (keep only 1 copy). From the error message you posted, the issue here is related to Google play services libraries. You should look into that (libraries named play-services-xxxx.aar).
Paid Help (Shameless Plug)
I provide a professional service for fixing this exact kind of issue. In case you (or anyone else) are not able to resolve such an issue themselves, feel free to contact me and get it solved.
I was facing the same problem after add admob in my project, here are 2 possible solutions:
Go to the file >> build settings and change the option internal to gradle
Open libs folders separately of both Facebook SDK and Google Play services and delete the matching files
It would be something like (support v4)
Google ads 11.2 has errors. It reuses certain jar classes .
On its own, it isnot an issue
Once you add in another google class, ie firebase, your done for.
There is a fix though. Google put out firebase 4.2 and ads 11.4