Can These iOS and Java Libraries Have Bindings to a Xamarin.Forms App?

Phil Wherrett 11

Hi Xamarin Experts,

Coming from a purely Windows/.NET background, I'm struggling to work out if the following two iOS and Java/Android libraries can have bindings to a Xamarin.Forms app:

mcumgr-ios

Android-nRF-Connect-Device-Manager

I have been trying to follow the steps for iOS here binding-swift, but haven't had much success to date. I haven't attempted Java/Andoid one as yet.

Any feedback or suggestions would be most welcome.

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 25,586 Reputation points Microsoft Vendor

2021-09-27T01:49:27.293+00:00
It needs four steps. May I ask about your step progress and is there any error messages?

Building the native library

Preparing the Xamarin metadata, which enables Xamarin tooling to generate C# classes

Building a Xamarin binding library using the native library and the metadata

Consuming the Xamarin binding library in a Xamarin application
Phil Wherrett 11 Reputation points

2021-09-27T23:31:50+00:00

Hi There,

Thanks for your response. As a complete noob to Xcode and Macs I'm at step 1 trying to build the library and generate the Swift header!

There are no errors - the source code builds, but I can't locate/find any framework headers. I assume I therefore need to add @objc attributes in the source code as per this:

If you have access to the code, you can decorate the required Swift member(s) with the @objc attribute and apply a few additional rules to let the Xcode build tools know that these members should be exposed to the Objective-C world and the header.

So, how do you go about doing that? And what are the 'additional rules' that are mentioned?
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 25,586 Reputation points Microsoft Vendor

2021-09-28T10:07:37.12+00:00

This means you could add changes to the third-party source code, 'additional rules' depends on what you want.
I check this mcumgr-ios repository , it use cocopods, you could download it, and run pod install. Its header is in the McuManager folder.
Phil Wherrett 11 Reputation points

2021-10-08T01:07:00.827+00:00

Hi There,
I think I'm progressing (slowly!). I have managed to install and build the McuManager/Example and have been able to locate the Headers.

Now if I run Sharpie I get the following output:

sharpie bind -sdk iphoneos -scope ./McuManager.framework/Headers ./McuManager.framework/Headers/McuManager-Swift.h
Parsing 1 header files...

Binding...
[write] ApiDefinitions.cs

Done.

As you can see it only generates ApiDefinitions.cs, not StructsAndEnums.cs as expected.

If I include all Headers, I get the following:

sharpie bind -sdk iphoneos -scope ./McuManager.framework/Headers ./McuManager.framework/Headers/*.h
Parsing 2 header files...

Binding...
[write] ApiDefinitions.cs

Binding Analysis:
Automated binding is complete, but there are a few APIs which have been flagged with [Verify] attributes hints:

ConstantsInterfaceAssociation (1 instance):

Once you have verified a Verify attribute, you should remove it from the binding source code. The presence of Verify attributes intentionally cause build
failures.

Done.

Still only the ApiDefinitions.cs file is generated. Does this seem correct, or am I missing something?
Adding this to a Binding Library Project, resolving the issues from above and building produces a number of errors which I'm not sure how to resolve/fix. Any further help/guidance would be great:
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 25,586 Reputation points Microsoft Vendor

2021-10-08T05:57:09.523+00:00

Do you have a correct framework? As this walkthrough show, the Swift framework need add to the project,i'm afraid you could check it.
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 25,586 Reputation points Microsoft Vendor

2021-10-14T03:15:35.827+00:00

The mcumgr-ios library is not really well formed and it is a little complicated to bind. It may occur some errors when parsing the API definitions. So, we recommend assisting support case or hiring a consultant.
https://support.serviceshub.microsoft.com/supportforbusiness This is a paid business, you could choose it.
Phil Wherrett 11 Reputation points

2021-10-20T00:53:55.257+00:00

Thanks for your assistance - I've come to a similar conclusion and now looking at other options rather than trying to bind these.
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 25,586 Reputation points Microsoft Vendor

2021-10-20T02:57:08.653+00:00

You are welcome.