I have two questions about Android Callable Wrappers which I hope you guys could answer.
Question 1. Xamarin auto-generates the following constructor in the ACW of a class:
public ConsumerService (java.lang.String p0, android.content.Context p1)
{
super (p0, p1);
if (getClass () == ConsumerService.class)
mono.android .TypeManager.Activate ("Test.Tizen.Droid.ConsumerService, Test.Tizen.Droid", "System.String, mscorlib:Android.Content.Context, Mono.Android ", this, new java.lang.Object[] { p0, p1 });
}
But then throws following exception on startup of the app: System.TypeLoadException: Could not load type '.mscorlib' from assembly 'Mono.Android , Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065'.
Which references to this part in the constructor: mscorlib:Android.Content.Context. Removing the "mscorlib:" fixes the exception, but my question is, why does it throw an exception in the first place since Xamarin auto-generates this?
Question 2. Can anyone tell me why Xamarin only takes the base class into account when generating the ACW of a derived class, and doesn't take the constructors of the derived class into account?
Related
I have previously used DryIOC as my IOC before, but I would like to try Splat for my IOC, would it be possible to combine these two?
I have tried making a LoginModule whom inherits the IModule so I have this on my LoginModule class:
public void OnInitialized(IContainerProvider containerProvider)
{
Locator.CurrentMutable.RegisterLazySingleton(() => new ServiceEntityMapper(), typeof(IServiceEntityMapper));
Locator.CurrentMutable.RegisterLazySingleton(() => new LoginAPIService(), typeof(ILoginAPIService));
Locator.CurrentMutable.RegisterLazySingleton(() => new LoginManager(
Locator.Current.GetService<IServiceEntityMapper>(),
Locator.Current.GetService<ILoginAPIService>()), typeof(ILoginManager));
}
and I have this for my view model constructor:
public LoginViewModel(INavigationService navigationService, ILoginManager loginManager = null) : base(navigationService)
{
LoginManager = loginManager ?? Locator.Current.GetService<ILoginManager>();
}
In result, I get this exception whenever I navigate to the page
{System.TypeLoadException: Could not resolve the signature of a virtual method
at System.Lazy`1[T].CreateValue () [0x00081] in <fe08c003e91342eb83df1ca48302ddbb>:0
at System.Lazy`1[T].LazyInitValue () [0x00080] in <fe08c003e91342eb83df1ca48302ddbb>:0
at System.Lazy`1[T].get_Value () [0x0003a] in <fe08c003e91342eb83df1ca48302ddbb>:0
at Splat.DependencyResolverMixins+<>c__DisplayClass7_0.<RegisterLazySingleton>b__0 () [0x00000] in <89c762f12a12451a8970372dc9921547>:0
at Splat.ModernDependencyResolver.GetService (System.Type serviceType, System.String contract) [0x00032] in <89c762f12a12451a8970372dc9921547>:0
at Splat.DependencyResolverMixins.GetService[T] (Splat.IDependencyResolver resolver, System.String contract)
From what I've seen Splat is a Service Locator not an actual DI Container. That said you certainly are not limited to the base Prism implementations, as those are provided to make it simple to adopt and get started. What I might suggest in your case is to create your own implementation of IContainerExtension and inherit from PrismApplicationBase.
You can see it's really not that much extra work in your App class by looking either at the implementations for Unity or DryIoc... there is a similar example using the Grace DI Container. Keep in mind that a couple of new API's have been added since the last preview, with a proposed breaking change to make IContainerRegistry have a fluent API.
Here, or here for a complete version, you can find a sample GRPC "Hello World" project for Unity. Only the first version, that is built for Unity and wrapped in a DLL is working perfectly fine in Unity IDE and on Standalone build. The Raw Grpc.Core files are referencing everything correctly in IDE but they have Marshaling problem.
Unfortunately, it cannot get build for UWP with IL2CPP backend. Unity builds the project and creates a .sln project. But Visual Studio always gives LNK2001 for GRPC properties on the final compilation.
Here are first error codes:
LNK2001 unresolved external _grpccsharp_init#0
LNK2001 unresolved external _grpccsharp_shutdonw#0
LNK2001 unresolved external _grpccsharp_version_string#0
...
Ok, thanks to #Sunius, I digged into it a little bit more. There are some points, I am going to add to the question:
There are two methods regarding referencing extern methods in GRPC C# package. They are named static and shared libs.
internal class DllImportsFromStaticLib
{
private const string ImportName = "__Internal";
[DllImport(ImportName)]
public static extern void grpcsharp_init();
[DllImport(ImportName)]
public static extern void grpcsharp_shutdown();
...
}
and
internal class DllImportsFromSharedLib
{
private const string ImportName = "grpc_csharp_ext";
[DllImport(ImportName)]
public static extern void grpcsharp_init();
[DllImport(ImportName)]
public static extern void grpcsharp_shutdown();
...
}
I tried to test it with the shared one, I got another linking error file which is a little bit different.
LNK2001 unresolved external _dlopen#8
LNK2001 unresolved external _dlsym#8
...
In two separate methods, extern methods are getting connected to the internal interface:
public NativeMethods(DllImportsFromStaticLib unusedInstance)
{
this.grpccsharp_init = DllImportsFromStaticLib.grpccsharp_init;
this.grpccsharp_shutdown = DllImportsFromStaticLib.grpccsharp_shutdonw;
...
}
and
public NativeMethods(DllImportsFromSharedLib unusedInstance)
{
this.grpccsharp_init = DllImportsFromSharedLib.grpccsharp_init;
this.grpccsharp_shutdown = DllImportsFromSharedLib.grpccsharp_shutdonw;
...
}
And which method will get called is defined here:
private static NativMethods LoadNativeMethodsUnity()
{
switch(PlatformApis.GetUnityRuntimePlatform())
{
case "IPhonePlayer":
return new NativeMethods(new NativeMethods.DllImportsFromStaticLib());
default:
return new NativeMethods(new NativeMethods.DllImportsFromSharedLib());
}
}
Some updates:
Thanks to #jsmouret, there is Stub.c file in his Grpc Github with fake methods, so Linker does not complain about Grpc_init methods anymore.
Next Error: dlopen, dlsym, dlerror:
First, I tried to use the same, Stub technique, but it did not help in this case, or maybe I did it wrong.
Thanks to #Sunius, I commented out all of "__Internal" dll import codes. So I am not getting any dlopen, dlsym, and dlerror errors.
Next Error: It happens from inside application, not the visual studio debugger. It tells me: "exception: to marshal a managed method, please add an attribute named 'MonoPInvokeCallback' to the method definition."
exception: error loading the embedded resource "Grpc.Core.roots.pem"
and
exception: To marshal a managed method, please add an attribute named 'MonoPInvokeCallback' to the method definition.
After I googled it, I know my options, but the question it, for which method should I do that?!
Thanks to my colleague Alice, #Sunius and #jsmouret, at the end, grpc works on UWP on Unity Platform through this steps:
Download Grpc.Core folder from Google Grpc Github.
Download Grpc Unity plugin from their official site.
Copy the runtime folder to your Grpc.Core folder. Please remove Grpc.Core.dll that you get from Grpc Unity Plugin, since we are using their source code.
Grpc should be in a folder called, Plugins in Unity, otherwise it will not be recognized.
Include this file in your runtime folder.
Include the Stub also from the Unity Plugin Inspector for WSA.
Find runtime .dll for Windows and include them in WSA from Unity Plugin Inspector.
By now, you should be getting _dlopen error.
Search through your Unity Solution with an IDE for "__Internal". There are not so many places, but comment them out. Also some methods that are depended on "__Internal"s, like dlopen and dlsym.
By now, you are not getting anymore build error but you need to make Grpc work.
Search for something like "DefaultSslRootsOverride" and comment out like below:
internal static class DefaultSslRootsOverride
{
const string RootsPemResourceName = "Grpc.Core.roots.pem";
static object staticLock = new object();
/// <summary>
/// Overrides C core's default roots with roots.pem loaded as embedded resource.
/// </summary>
public static void Override(NativeMethods native)
{
lock (staticLock)
{
//var stream = typeof(DefaultSslRootsOverride).GetTypeInfo().Assembly.GetManifestResourceStream(RootsPemResourceName);
//if (stream == null)
//{
// throw new IOException(string.Format("Error loading the embedded resource \"{0}\"", RootsPemResourceName));
//}
//using (var streamReader = new StreamReader(stream))
//{
// var pemRootCerts = streamReader.ReadToEnd();
// native.grpcsharp_override_default_ssl_roots(pemRootCerts);
//}
}
}
}
Search for something like "static void HandWrite" and add an attribute like something in below:
[MonoPInvokeCallback(typeof(GprLogDelegate))]
private static void HandleWrite(IntPtr fileStringPtr, int line, ulong threadId, IntPtr severityStringPtr, IntPtr msgPtr)
{
try
{
var logger = GrpcEnvironment.Logger;
string severityString = Marshal.PtrToStringAnsi(severityStringPtr);
string message = string.Format("{0} {1}:{2}: {3}",
threadId,
Marshal.PtrToStringAnsi(fileStringPtr),
line,
Marshal.PtrToStringAnsi(msgPtr));
switch (severityString)
{
case "D":
logger.Debug(message);
break;
case "I":
logger.Info(message);
break;
case "E":
logger.Error(message);
break;
default:
// severity not recognized, default to error.
logger.Error(message);
break;
}
}
catch (Exception e)
{
Console.WriteLine("Caught exception in native callback " + e);
}
}
I guess, you are done. In case, it did not work for your UWP, let me know, maybe I can help. :)
It looks like your plugin uses "__Internal" P/Invoke to call those native functions:
https://github.com/grpc/grpc/blob/befc7220cadb963755de86763a04ab6f9dc14200/src/csharp/Grpc.Core/Internal/NativeMethods.Generated.cs#L542
However, the linker cannot locate those functions and thus fails. You should change that code to either specify the DLL file name where the functions are implemented, or drop the source files with definitions for those functions into your Unity project. Or, if that code path isn't actually invoked (since you said it works on the standalone player), #ifdef it out from UWP build.
You can find more information about "__Internal" P/Invoke here:
https://docs.unity3d.com/Manual/windowsstore-plugins-il2cpp.html
I created a Xamarin Binding Project for Android, and generated the Bindings for the .aar file. So far, so good.
When I first called a constructor which throws an Exception, a build error occured:
.../XamVideoCaptureReader.java(9,9): Error: error: unreported exception ReaderException; must be caught or declared to be thrown super (p0, p1, p2); (AndroidTest)
On the following code part:
public XamVideoCaptureReader (int p0, com.digimarc.dms.readers.ReaderOptions p1, com.digimarc.dms.readers.image.CaptureFormat p2)
{
super (p0, p1, p2);
...
}
I think the error is pretty self explanatory, but I can't find a way to fix it. The super call has to be wrapped in a try catch, or even better: a throws ReaderException should be added to the constructor signature.
Has anyone experienced this error before and could solve it? Or is this a bug of Xamarin?
Please help me with this one, I've been writing a console applicaiton using the AsyncCtpLibrary and the C#5 ctp compiler. First time I got to actually running a code which awaits, I got this:
System.BadImageFormatException was unhandled
Message=An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)
Source=AsyncCtpLibrary
StackTrace:
Server stack trace:
at [...].<Execute>d__1c.MoveNext()
at [...].Execute()
at [...].<Move>d__1d.MoveNext() in[..]:line 266
Exception rethrown at [0]:
at System.Runtime.CompilerServices.AsyncVoidMethodBuilder.<SetException>b__1(Object state)
at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
InnerException:
Am I missing a dll to be referenced?
important new stuff
My failing method looks like this:
public async override Task<bool> Execute()
{
//do stuff
await stuff;
//do other stuff
await base.Execute()
//do other stuff
return true;
}
I've followed Jon Skeet's advice trying to recreate the mistake little by little, and now I can tell that the await base.Execute() line is the killer! If I comment that line out, everything runs, if I leave it in, calling my method fails IMMEDIATELY (not when reaching the base.Execute()). So I assume the ctp compiler does something freaky. Why? What should I never do? How big is the bug?
old stuff:
EDIT:
As for 32bit/64bit issue, my system is 32bit (inside a virtual machine, mind you), and as far as I know AsyncCtpLibrary.dll doesn't contain unmanaged code. All my projects (class libraries and single console app) all have build tabs like this:
What can possibly be still wrong?
EDIT:
I also checked the Fusion log viewer, the AsyncCtpLibrary is loaded without any error:
*** Assembly Binder Log Entry (6/10/2011 # 9:04:11 PM) ***
The operation was successful.
Bind result: hr = 0x0. The operation completed successfully.
Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable C:\Users\Daver\Documents\Visual Studio 2010\Projects\[...]\bin\Debug\MyApp.exe
--- A detailed error log follows.
=== Pre-bind state information ===
LOG: User = WIN-N74LV38NLV3\Daver
LOG: DisplayName = AsyncCtpLibrary, Version=1.0.4107.18181, Culture=neutral, PublicKeyToken=31bf3856ad364e35
(Fully-specified)
LOG: Appbase = file:///C:/Users/Daver/Documents/Visual Studio 2010/Projects/[...]/bin/Debug/
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = MyApp.exe
Calling assembly : MyLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\Users\Daver\Documents\Visual Studio 2010\Projects\[...]\bin\Debug\MyApp.exe.Config
LOG: Using host configuration file:
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Post-policy reference: AsyncCtpLibrary, Version=1.0.4107.18181, Culture=neutral, PublicKeyToken=31bf3856ad364e35
LOG: GAC Lookup was unsuccessful.
LOG: Attempting download of new URL file:///C:/Users/Daver/Documents/Visual Studio 2010/Projects/[...]/bin/Debug/AsyncCtpLibrary.DLL.
LOG: Assembly download was successful. Attempting setup of file: C:\Users\Daver\Documents\Visual Studio 2010\Projects\[...]\bin\Debug\AsyncCtpLibrary.dll
LOG: Entering run-from-source setup phase.
LOG: Assembly Name is: AsyncCtpLibrary, Version=1.0.4107.18181, Culture=neutral, PublicKeyToken=31bf3856ad364e35
LOG: Binding succeeds. Returns assembly from C:\Users\Daver\Documents\Visual Studio 2010\Projects\[...]\bin\Debug\AsyncCtpLibrary.dll.
LOG: Assembly is loaded in default load context.
I also checked the IL code of the <Execute>d__1c compiler-generated class' MoveNext() method, and the only assemblies it references ([assemblyName]) are mscorlib, System.Core, and AsyncCtpLibrary.
I checked the manifest of both my dll and AsyncCtpLibrary, mine said .corflags 0x00000003 // ILONLY 32BITREQUIRED, AsyncCtpLibrary said .corflags 0x00000009 // ILONLY, I'm unsure if this can be the problem.
Please help, I'm out of ideas!
EDIT: I've heard back from the compiler team, who have confirmed it as a bug. It had already been fixed in their codebase, so hopefully we'll see that fix in the next release / beta / CTP. The fix isn't going to be back-ported to "normal" VS2010 as it's a pretty unusual set of circumstances, at least before async.
EDIT: Okay, I've now got a really short but complete program which demonstrates the problem. I believe it's a mixture of generics and calling a base method:
using System;
using System.Threading.Tasks;
public abstract class AsyncAction<T>
{
public virtual Task<T> Execute()
{
// We never get this far
Console.WriteLine("Execute called");
return null;
}
}
public class BoolAction : AsyncAction<bool>
{
public async override Task<bool> Execute()
{
return await base.Execute();
}
}
class Test
{
static void Main()
{
BoolAction b = new BoolAction();
b.Execute();
}
}
EDIT: Okay, I've come up with a workaround. Basically, to call the base class method non-virtually, the compiler creates a synthetic method in BoolAction. It gets that slightly wrong, but we can get it right:
public class BoolAction : AsyncAction<bool>
{
public async override Task<bool> Execute()
{
return await BaseExecute();
}
private Task<bool> BaseExecute()
{
return base.Execute();
}
}
So whenever you were writing base.Execute, write BaseExecute and insert that extra method. It's not too bad a workaround, until the team fix the bug.
EDIT: I've simplified the example a bit - you don't need any overrides, and in particular you don't need the base class to expose a Task<T>. A call to any virtual base.Foo method will do it:
public abstract class AsyncAction<T>
{
public virtual T GetT()
{
return default(T);
}
}
public class BoolAction : AsyncAction<bool>
{
#pragma warning disable 1998 // We're not awaiting anything
public async void Execute()
{
base.GetT();
}
#pragma warning restore 1998
}
class Test
{
static void Main()
{
BoolAction b = new BoolAction();
b.Execute();
}
}
EDIT: Contrary to my previous thoughts, this does affect iterators as well. No async CTP required...
public abstract class Base<T>
{
public virtual T GetT()
{
return default(T);
}
}
public class Derived : Base<bool>
{
public System.Collections.IEnumerator Foo()
{
base.GetT();
yield break;
}
}
class Test
{
static void Main()
{
Derived d = new Derived();
d.Foo().MoveNext();
}
}
EDIT: And it affects anonymous functions too...
using System;
public abstract class Base<T>
{
public virtual T GetT()
{
return default(T);
}
}
public class Derived : Base<bool>
{
public void Foo()
{
Action x = () => base.GetT();
x();
}
}
class Test
{
static void Main()
{
Derived d = new Derived();
d.Foo();
}
}
You are hitting known VS 2010 bug
https://connect.microsoft.com/VisualStudio/feedback/details/626550/badimageformatexception-on-simple-program-using-generics-and-lambdas
This exception often occurs when you try and load a 32 bit DLL in a 64 bit environment.
If you are running on a 64 bit OS try changing your projects settings to compile directly for x86 (rather than AnyCPU).
(This might sound backwards, but it's because if you are loading an external 32 bit DLL you need to force your whole project to be 32 bit.)
I'm trying to figure out how to wrap a boost::function member (used as an event callback) of an unmanaged class with a C++/CLI class event. I do not have control over the unmanaged class. All I can do is figure out how to write the C++/CLI class properly.
Here's the example unmanaged class:
class X
{
public:
boost::function<void (double)> XChanged;;
void Set(double x)
{
XChanged(x)
}
};
I've tried many things, but I keep running into problems. I'm sure it's easier than it appears to be. Any help would be greatly appreciated!
CLI probably won't let you declare a boost::function as a static member. Make it a pointer:
boost::function<void(double> *XChanged;
Then allocate/deallocate in the constructor and finalizer and call it with (*XChanged)(arg);