Assembly generation failed - does not have a strong name - xamarin

Im getting the following error in the Portable Class Library (PCL) in Xamarin, how to resolve this,?
Assembly generation failed -- Referenced assembly 'Xamarin.Forms.Core' does not have a strong name

Xamarin.Forms assemblies distributed through nuget.org are not strong-signed.
You're trying to strong-sign your application assembly, and this require all dependencies to be strong-signed too. That's the problem you're seeing.
IMHO, strong-signing application adds none to very little value in mobile, esp on Android and iOS.

Related

Resource-related error condition in Windows Forms C++ application

I am working on a legacy Windows Forms application using VS 2008 under C++ and face a weird problem. The form uses an ImageList object, to which two bitmap images have been added. At run-time, I get the following error in Debug mode (in the Release mode, the application just doens't launch):
An unhandled exception of type 'System.Resources.MissingManifestResourceException' occurred in mscorlib.dll
Additional information: Could not find any resources appropriate for the specified culture or the neutral culture.
Make sure "MyApp.Form1.resources" was correctly embedded or linked into assembly "MyApp" at compile time,
or that all the satellite assemblies required are loadable and fully signed.
The crash occurs at the first line of this block:
this->imageList1->ImageStream = (__try_cast<System::Windows::Forms::ImageListStreamer* >(resources->GetObject(S"imageList1.ImageStream")));
this->imageList1->TransparentColor = System::Drawing::Color::Transparent;
this->imageList1->Images->SetKeyName(0, S"Nok32.png");
this->imageList1->Images->SetKeyName(1, S"Ok32.png");
This is pretty puzzling, because I copied the application from an existing one which works fine. I just changed the namespaces. And if I remove the two images from the list, the application works.
I found several posts on forums about this or similar problems, but none could really help me. I don't think that Visual Studio can be blamed. I tried with frameworks 2.0 and 3.0, to no avail. Fully comparing the sources of both applications, I can't see a significant difference.
Any hint ?
Solved: there was an old namespace left in the project file (.vcproj) !

Xamarin Shared Library namespace cannot be found

My shared library cannot resolve using RestSharp; among other related namespaces. RestSharp is an installed package and is resolvable in the Droid/iOS projects but cannot be found in the Shared Library. I know this works because I'm using RestSharp in a MonoGame project in the same way. The shared library is referenced in the Droid/iOS projects but still fails during compilation.
Any advice? I tried clean all.
Update I created a new Cross Platform Native app solution and I was able to reference in my shared library without issue. That original project is a bit older and was created with PCL originally. I still want to know why it's not working in my original solution.
I continued to have lots of namespace and type not found issues. Once I showed warnings instead of just errors I found that the csproj was missing. After removing the reference in the native apps and re-adding the issue was resolved. Quite frusterating.

Error MT2001: Could not link assemblies. Reason: Error while processing references

I'm getting this error trying to build a Xamarin.iOS project referencing a .NET Standard 2.0 library.
None of the MT2001 issues online seem to have this specific "Error while processing references" reason, so I'm at a loss as to how to diagnose this. I've tweaked and fiddled about as much as any one person can and stay sane, but I'm really in the dark.
Can anyone out there point me in a direction?
Adding -v -v -v -v to "Additional mtouch arguments" in the project iOS Build settings will help diagnose the issue. After that, you can search the build output for MT2001 and view the inner exceptions. Obviously, each project may differ as to what assembly causes the linker to fail. You may need to add, remove or fix your references based on the output.
For example, I was trying to use SignalR from AspNetCore 2.1, which has a dependency on System.Threading.Tasks.Extensions 4.5.1 in my project, which it seems Mono does not yet support. Mono does not provide its own version of the assembly yet, so when mtouch goes to link the assembly, it's unable to do so and throws an exception:
Mono.Cecil.AssemblyResolutionException: Failed to resolve assembly: 'System.Threading.Tasks.Extensions, Version=4.2.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
Removing all references to this assembly (and therefore the whole feauture in my case) allowed the build and linking to succeed.
I've found that I get this when using a Xamarin library that is dependent on System.Reactive 4.1.0. There's a bug in there associated with System.Threading.Tasks.Extensions, and since it is a library I'm writing, I had to roll back to System.Reactive 4.0.0.
For me the error is as follows.
one of the package is mentioned in package.config file but it was not available in packages. So i added the missing package from nuget and the app works fine

Xamarin binding for AWS SDK

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.

MTOUCH: error MT0034 Xamarin.iOS and Catel

I am getting this error when I try to compile my Xamarin.iOS app. I am referencing Catel.MVVM and Catel.Fody.
Any idea what to do?
MTOUCH: error MT0034: Cannot include both 'monotouch.dll' and 'Xamarin.iOS.dll' in the same Xamarin.iOS project - 'Xamarin.iOS.dll' is referenced explicitly, while 'monotouch.dll' is referenced by 'Catel.MVVM, Version=4.4.0.0, Culture=neutral, PublicKeyToken=null'.
One of your project parts uses the UnifiedAPI (Xamarin.iOS.dll) and another one uses the Classic API (monotouch.dll). They can not be both part of the project.
You goal should be to use the UnifiedAPI/ Xamarin.iOS.dll instead of the old monotouch assembly because with the new one you are able to get your app in the store. Xamarin Studio is able to convert your project to the UnifiedAPI. I am not sure but take a look under Project > "Convert to UnifiedAPI" or something like that.

Resources