[Bug] iOS - "Exception of type 'Foundation.You_Should_Not_Call_base_In_This_Method' was thrown."

[WanftMoon]

Describe the bug
Project in xamarin forms with ble.net, when calling start in iOS, the following exception is thrown:

"Exception of type 'Foundation.You_Should_Not_Call_base_In_This_Method' was thrown."

obs: Need guidance in case i'm missing something to setup the dfu correctly in iOS, because the same exception is not happening in Android. The process starts ok

at Laerdal.Dfu.Bindings.iOS.DFUFirmware..ctor (Foundation.NSUrl urlToZipFile, Foundation.NSError& error) [0x0000d] in /Users/runner/work/1/s/Laerdal.Dfu.Bindings.iOS/obj/Release/xamarin.ios10/iOS/Laerdal.Dfu.Bindings.iOS/DFUFirmware.g.cs:119 
  at Laerdal.Dfu.DfuServiceInitiatorDelegate..ctor (Laerdal.Dfu.DfuInstallation dfuInstallation) [0x00010] in /_/Laerdal.Dfu/Platforms/iOS/DfuServiceInitiatorDelegate.cs:29 
  at Laerdal.Dfu.DfuInstallation.Start (Laerdal.Dfu.DfuConfiguration configuration) [0x00034] in /_/Laerdal.Dfu/Platforms/iOS/DfuInstallation.cs:33 
  at Viewmodel.BleConnectedDeviceViewModel.FlashDevice (System.Object arg) [0x0010c] 

To Reproduce
Steps to reproduce the behavior:

1. Create Xamarin.Forms project
2. Include ble library and configure it to scan a device
3. Add Laerdal.Dfu
4. Configure install

dfuInstall = new DfuInstallation(deviceAddress /*59:A1:A6:62:41:7A*/, fi.FullName);

dfuInstall.DfuErrorReceived += OnDfuErrorOccured;
dfuInstall.DfuStateChanged += OnDfuStateChanged;
dfuInstall.DfuProgressChanged += OnDfuProgressChanged;

dfuInstall.Start(new DfuConfiguration() { DisableNotification = true, Foreground = false });

Expected behavior
The install to start like it does in Android.

Screenshots
N/A

Desktop (please complete the following information):

• OS: MacOS Sonoma
• Versions
  -- ble.net 1.2.1
  -- Laerdal.Dfu 1.27.2-xamarin-10.45630
  -- Xamarin.Essentials - 1.8.1
  -- Xamarin.Forms - 5.0.0.2622

Smartphone (please complete the following information):

• Device: iPhone 8+
• OS: 16
• Browser N/A
• Version N/A

Additional context
N/A

[schneifa]

We are currently discussing this issue in #27.

[WanftMoon]

Oki, for those interested. The issue is in: https://github.com/Laerdal/Laerdal.Dfu.Bindings.iOS/tree/master

@schneifa @framinosona @ksidirop-laerdal #27

I re-did the bindings locally, so if anyone that maintain the project and would like to check the changes below and also update all the native binding and references, that would make people happy.

1. Project linking against a xcframework - set to no binding Embedding (right now is embedding)
   <NoBindingEmbedding>true</NoBindingEmbedding>

2. The api definition needs tweaking:
   a. Interfaces just need the BaseType (the exception reported was because there were [Model] everywhere which generates a model with no code besides the exception being thrown

// @interface DFUFirmware : NSObject
[BaseType(typeof(NSObject), Name = "_TtC9NordicDFU11DFUFirmware")]
[DisableDefaultCtor]
interface DFUFirmware

b. Protocols, there are only 4 of them. I've left the [BaseType][Protocol][Model]

// @protocol DFUPeripheralSelectorDelegate
[BaseType(typeof(NSObject), Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
[Protocol(Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
[Model(Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
interface DFUPeripheralSelectorDelegate

att.

[ISSPRO-Eng]

Thank you for the work @WanftMoon !!!! Hopefully the local project is updated soon :)

[algrm]

@WanftMoon thanks for your insights. I don't think it fully applies here, as AppDefinition.cs here is different from the one in Laerdal.Dfu.Bindings.iOS. And thanks @framinosona for sharing this work, extremely useful to me.
After several days on this topic, here is what I did:

• Rebuild separate nuget packages for both bindings, from Laerdal's sources. I removed the net6 support and applied @WanftMoon advices on the iOS package. The iOS library must be build on a Mac.
• Create a new MAUI/.NET 8 library and copy Laerdal.Dfu source in it. This is mostly a matter or putting the files in different folders. I use the binding packages as dependencies.

I stumbled today on another problem (undefined symbol for the ios Nordic functions). I solved it by changing the path of the framework dependencies and make them point to the arm64 framework in the Carthage folder.

I hope this might help. Too many changes to make a PR but I'll be happy to share my work if asked.

[neicureuil]

Hi,
I'm facing the same issue, I tried to compile the bindings my self and following the instructions of @WanftMoon but I don't really understand what need to be change in the iOS binding.

I have tried to remove the "[Model]" attribute but same error : "Foundation.You_Should_Not_Call_base_In_This_Method".

Can you provide a patch or help please ?

[WanftMoon]

Hi, I'm facing the same issue, I tried to compile the bindings my self and following the instructions of @WanftMoon but I don't really understand what need to be change in the iOS binding.

I have tried to remove the "[Model]" attribute but same error : "Foundation.You_Should_Not_Call_base_In_This_Method".

Can you provide a patch or help please ?

if you are re-doing the native binding: just make sure you edit your api definition file as follows:

a. Interfaces just need the BaseType (the exception reported was because there were [Model] everywhere which generates a model with no code besides the exception being thrown

// @interface DFUFirmware : NSObject
[BaseType(typeof(NSObject), Name = "_TtC9NordicDFU11DFUFirmware")]
[DisableDefaultCtor]
interface DFUFirmware

b. Protocols, there are only 4 of them. I've left the [BaseType][Protocol][Model]

// @protocol DFUPeripheralSelectorDelegate
[BaseType(typeof(NSObject), Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
[Protocol(Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
[Model(Name = "_TtP9NordicDFU29DFUPeripheralSelectorDelegate_")]
interface DFUPeripheralSelectorDelegate

[neicureuil]

That's what I did but I got the same error :

[0:] Exception choosing file: Foundation.You_Should_Not_Call_base_In_This_Method: Exception of type 'Foundation.You_Should_Not_Call_base_In_This_Method' was thrown.
  at Laerdal.Dfu.Bindings.iOS.DFUFirmware..ctor (Foundation.NSUrl urlToZipFile, Foundation.NSError& error) [0x0000d] in /Users/runner/work/1/s/Laerdal.Dfu.Bindings.iOS/obj/Release/xamarin.ios10/iOS/Laerdal.Dfu.Bindings.iOS/DFUFirmware.g.cs:119 
  at Laerdal.Dfu.DfuServiceInitiatorDelegate..ctor (Laerdal.Dfu.DfuInstallation dfuInstallation) [0x00010] in /Users/neicureuil/Documents/Laerdal.Dfu/Laerdal.Dfu/Platforms/iOS/DfuServiceInitiatorDelegate.cs:29 
  at Laerdal.Dfu.DfuInstallation.Start (Laerdal.Dfu.DfuConfiguration configuration) [0x00034] in /Users/neicureuil/Documents/Laerdal.Dfu/Laerdal.Dfu/Platforms/iOS/DfuInstallation.cs:33 
  at Nordic.Sdk.Impl.Dfu.DfuManager.Start (System.String deviceAddress, System.String firmwareZipFile) [0x00062] in C:\Users

Here is my modified ApiDefinition.cs, do you see anything that I forgot ? https://gist.github.com/neicureuil/d2893c384437422c5a4f1c6bbb20f677

[WanftMoon]

That's what I did but I got the same error :

[0:] Exception choosing file: Foundation.You_Should_Not_Call_base_In_This_Method: Exception of type 'Foundation.You_Should_Not_Call_base_In_This_Method' was thrown.
  at Laerdal.Dfu.Bindings.iOS.DFUFirmware..ctor (Foundation.NSUrl urlToZipFile, Foundation.NSError& error) [0x0000d] in /Users/runner/work/1/s/Laerdal.Dfu.Bindings.iOS/obj/Release/xamarin.ios10/iOS/Laerdal.Dfu.Bindings.iOS/DFUFirmware.g.cs:119 
  at Laerdal.Dfu.DfuServiceInitiatorDelegate..ctor (Laerdal.Dfu.DfuInstallation dfuInstallation) [0x00010] in /Users/neicureuil/Documents/Laerdal.Dfu/Laerdal.Dfu/Platforms/iOS/DfuServiceInitiatorDelegate.cs:29 
  at Laerdal.Dfu.DfuInstallation.Start (Laerdal.Dfu.DfuConfiguration configuration) [0x00034] in /Users/neicureuil/Documents/Laerdal.Dfu/Laerdal.Dfu/Platforms/iOS/DfuInstallation.cs:33 
  at Nordic.Sdk.Impl.Dfu.DfuManager.Start (System.String deviceAddress, System.String firmwareZipFile) [0x00062] in C:\Users

Here is my modified ApiDefinition.cs, do you see anything that I forgot ? https://gist.github.com/neicureuil/d2893c384437422c5a4f1c6bbb20f677

Looking at your file, you didn't. You have several classes that maps the sdk interfaces marked as protocol.

// @interface DFUFirmware : NSObject
        [BaseType (typeof(NSObject), Name = "_TtC13iOSDFULibrary11DFUFirmware")]
        [Protocol (Name = "_TtC13iOSDFULibrary11DFUFirmware")]
        [DisableDefaultCtor]
        interface DFUFirmware

[neicureuil]

Thanks for your help, it was a nuget cache issue.
With your modification, I got an other error :

[0:] Exception choosing file: System.Exception: Could not create an native instance of the type 'Laerdal.Dfu.Bindings.iOS.DFUFirmware': the native class hasn't been loaded.
It is possible to ignore this condition by setting ObjCRuntime.Class.ThrowOnInitFailure to false.
  at Foundation.NSObject.InitializeObject (System.Boolean alloced) [0x000b2] in /Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/src/Xamarin.iOS/Foundation/NSObject2.cs:360 
  at Foundation.NSObject..ctor (Foundation.NSObjectFlag x) [0x0000d] in /Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/src/Xamarin.iOS/Foundation/NSObject2.cs:201 

It seems that the native lib isn't loaded. Do you have any idea why I get this error ?

[WanftMoon]

Thanks for your help, it was a nuget cache issue. With your modification, I got an other error :

[0:] Exception choosing file: System.Exception: Could not create an native instance of the type 'Laerdal.Dfu.Bindings.iOS.DFUFirmware': the native class hasn't been loaded.
It is possible to ignore this condition by setting ObjCRuntime.Class.ThrowOnInitFailure to false.
  at Foundation.NSObject.InitializeObject (System.Boolean alloced) [0x000b2] in /Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/src/Xamarin.iOS/Foundation/NSObject2.cs:360 
  at Foundation.NSObject..ctor (Foundation.NSObjectFlag x) [0x0000d] in /Library/Frameworks/Xamarin.iOS.framework/Versions/16.4.0.23/src/Xamarin.iOS/Foundation/NSObject2.cs:201 

It seems that the native lib isn't loaded. Do you have any idea why I get this error ?

You might want to check that the xcframework is being copied to the correct location (referencing the ios native binding in your ios project might help).
Also, check that native binding is not embedding.
<NoBindingEmbedding>true</NoBindingEmbedding>

[neicureuil]

It's work now !
I have to directly reference the xcframework in my iOS app project. Is there a way not to have to do this ?

Thank you for your help, you save me !

[ISSPRO-Eng]

@algrm or @neicureuil

Any chance you could share the updated Nuget Package with me? I do not have any experience on building or editing NuGet Packages, so I am still waiting on an update to the master Nuget.

[ISSPRO-Eng]

Detected package downgrade: Laerdal.Dfu.Bindings.iOS from 4.13.0.43857 to 4.13.0.88. Reference the package directly from the project to select a different version.

@algrm @WanftMoon @neicureuil

Getting this message when trying to add a newly built iOS Bindings Library to my app to replace the 4.13.0.43857 version that Laerdal.Dfu 1.27.8 relies on

[WanftMoon]

Detected package downgrade: Laerdal.Dfu.Bindings.iOS from 4.13.0.43857 to 4.13.0.88. Reference the package directly from the project to select a different version.

@algrm @WanftMoon @neicureuil

Getting this message when trying to add a newly built iOS Bindings Library to my app to replace the 4.13.0.43857 version that Laerdal.Dfu 1.27.8 relies on

Don't use both, since you build a native binding, you will need to do the same with the wrapper (laerdal.dfu). Just get Laerdal.Dfu code, add it to the solution, then update the references.