BlinkInput Xamarin SDK

This is BlinkInput Xamarin implementation based on native iOS and Android BlinkInput SDKs.

Integration into Xamarin Forms project

Steps for integrating BlinkInput into your Xamarin Forms project:

1. In both your Core, Droid and iOS projects, add BlinkInput.Forms NuGet package as a reference.
2. In your Droid project, update your MainActivity.cs in a following way:
   • update your MainActivity class so that it implements Microblink.Forms.Droid.IMicroblinkScannerAndroidHostActivity. This interface specifies 2 properties and 1 method that you must implement:
     • HostActivity property must return reference to current host activity.
     • ScanActivityRequestCode property must return integer that will be used as request code for Android's StartActivityForResult invocation
     • ScanningStarted method will be called just before scanning starts. It will receive currently used MicroblinkScannerImplementation as a parameter. You should save a reference to this object because you will need it later in your implementation of OnActivityResult
   • override Activity's method OnActivityResult and pass its parameters to reference of MicroblinkScannerImplementation
3. Your iOS project does not need any modifications.
4. In your Core project, obtain a reference to IMicroblinkScannerFactory using a DependencyService
5. Use a factory to create an instance of IMicroblinkScanner.
6. Use the dependency service to create recognizer you wish to use
7. Subscribe to Messages.ScanningDoneMessage that will inform you whether the scanning has completed or was cancelled by end user
8. Using on or more of recognizer objects obtained in step 6., create an instance IRecognizerCollection using IRecognizerCollectionFactory obtained via DependencyService
9. Create a settings object for desired UI overlay
10. Start scanning by invoking method Scan on instance of IMicroblinkScanner

Xamarin Forms sample app

Xamarin Forms sample app is available here.

Integration into native Android project

In your native Android project, add reference to BlinkInput.Android.Binding NuGet package and follow the integration instructions for BlinkInput Android SDK.

Native Android sample app

Native Android sample app is available here.

Integration into native iOS project

In your native iOS project, add reference to BlinkInput.iOS.Binding NuGet package and follow the integration instructions for BlinkInput iOS SDK.

Native iOS sample app

Native iOS sample app is available here.

Integration via Binding projects

If you do not wish to use BlinkInput NuGet packages, you can directly reference binding projects in your solutions. Just make sure that following conditions are met:

• all large binary files have been checked out
  • to ensure that all files have been checked out, please make sure that you have installed Git Large File Storage and that you have fetched all LFS files with git lfs pull command.
• your solution has referenced all dependencies of the project that you are referencing

Directory and files summary

• Binding - Xamarin iOS and Android Binding Libraries and Xamarin Forms project from which all mentioned NuGet packages were built
• Samples - Xamarin.iOS, Xamarin.Android and Xamarin.Forms sample applications

Advanced topics

Updating native binding libraries

Android

1. Download latest AAR from Android SDK repository
2. Replace Binding/Android/Jars/LibBlinkInput.aar with latest AAR
3. Open Binding/Forms/BlinkInput.Forms/BlinkInput.Forms.sln solution
4. If needed, update Transforms/Metadata.xml in AndroidBinding project.
5. Right-click the AndroidBinding project, select Options, under NuGet Package section select Metadata
6. Update Version on tab General
7. Update Release notes on tab Details
8. Rebuild the AndroidBinding project

iOS

1. Download latest Microblink.bundle and Microblink.framework from iOS SDK repository

2. Replace Binding/iOS/Microblink.bundle and Binding/iOS/Microblink.framework with latest versions

3. Generate new ApiDefinitions.cs and StructsAndEnums.cs with latest version of Objective Sharpie, but DO NOT OVERWRITE existing ApiDefiniton.cs and Structs.cs

   • you can generate new ApiDefinitions.cs and StructsAndEnums.cs with following command (replace iphoneos13.3 with latest SDK you have on your Mac):

   cd Binding/iOS
   sharpie bind -sdk iphoneos13.3 Microblink.framework/Headers/Microblink.h -scope Microblink.framework/Headers -namespace Microblink -c -F .
   

4. Manually merge new structures from generated StructsAndEnums.cs into existing Structs.cs while fixing compile errors

   • sharpie generates enums with underlying types such as nuint or nint which are not supported by latest version of C# - you must replace those with uint or int types.

5. Manually merge new API classes from generated ApiDefinitions.cs into existing ApiDefinition.cs

   • note that diff between those two files may be quite large, as ApiDefinition.cs has been manually edited to ensure correct compilation and correct exposure of all native SDK features. Focus only on adding new recognizers and parsers. Usually it shuold not be necessary to add other classes.

6. Open Binding/Forms/BlinkInput.Forms/BlinkInput.Forms.sln solution

7. From iOSBinding project remove Microblink.bundle and re-add it back

   • this will ensure that all new resources from new bundle are correctly added to the project
   • also make sure that all resources within added Microblink.bundle have BuildAction set to BundleResource

8. Right-click the iOSBinding project, select Options, under NuGet Package section select Metadata

9. Update Version on tab General

10. Update Release notes on tab Details

11. Rebuild the iOSBinding project and fix any compile errors that may have been introduced in steps 4. and 5.

Updating Xamarin Forms core and platform implementations

1. Ensure that both Android and iOS native binding libraries have been updated as explained above
2. Open Binding/Forms/BlinkInput.Forms/BlinkInput.Forms.sln solution
3. Right-click the BlinkInput.Forms.Core project, select Options, under NuGet Package section select Metadata
4. Update Version on tab General
5. Update Release notes on tab Details
6. Do the same for BlinkInput.Forms.Android, BlinkInput.Forms.iOS and BlinkInput.Forms.NuGet projects
7. in BlinkInput.Forms.Core add interfaces for new functionality (e.g. new recognizer)
8. add implementation for those interfaces in BlinkInput.Forms.Android and BlinkInput.Forms.iOS projects
9. rebuild both BlinkInput.Forms.Core, BlinkInput.Forms.Android and BlinkInput.Forms.iOS projects

Creating updated NuGet packages

1. Ensure that all projects have been updated as described above
   • this includes Android and iOS native binding libraries and Xamarin Forms core and platform implementations libraries
2. Open Binding/Forms/BlinkInput.Forms/BlinkInput.Forms.sln solution
3. Make sure Release build type is selected in Visual Studio
4. Right-click on BlinkInput.Forms.NuGet project and select Create NuGet package
   • all projects will be built and their respective NuGet packages will be created in their bin/Release folder
5. Upload packages to NuGet

Android custom integration

This section describes how to create your scan activity with BlinkInput SDK, natively in Android and wrap it to Xamarin. For that purpose, we have prepared AndroidCustomUI sample.

Steps to wrap custom functionality to Xamarin:

1. Implement it natively for Android - create Android library:
   • make sure that you are not using any resources from the BlinkInput Android SDK in resource files inside your library, otherwise, you will get compile errors while generating Xamarin bindings from Android library
   • we have created BlinkInputWrapper Android Studio project which contains LibBlinkInputWrapper Android library module with custom scan activity
2. Build .aar archive from the library module:
   • we have built LibBlinkInputWrapper-release.aar from our Android library module
3. Create a new Xamarin Bindings Library for Android:
   • add a dependency to BlinkInput.Android.Binding nuget package
   • add .aar to Jars folder and set the Build Action for .aar to LibraryProjectZip
   • we have prepared CustomUIBinding project inside CustomUISample solution
4. You can use the Bindings Library in the application project:
   • first, add a reference to the created Bindings Library
   • add a dependency to BlinkInput.Android.Binding
   • we have prepared sample application project CustomUIApp inside CustomUISample solution