Build Unity Library

Unity 2022.3.17f1 may throw the following error when integrating with React Native or Flutter:

AndroidJavaException: java.lang.NoSuchFieldError: no "Ljava/lang/Object;" field "mUnityPlayer" in class

This issue has been fixed in Unity 2022.3.19f1.

1. Prepare Android Library (Unity Project)

1. Export Android Project

Export the Android project from Unity (select Export Project in Build Settings).

2. Update AndroidManifest.xml

Navigate to:

<build-folder>/unityLibrary/src/main/AndroidManifest.xml

Remove the <intent-filter> section associated with the Unity launcher:


<intent-filter>
  <category android:name="android.intent.category.LAUNCHER" />
  <action android:name="android.intent.action.MAIN" />
</intent-filter>

3. Build Android App Library with Gradle


cd <build-folder>
export JAVA_HOME=<unity-folder>/PlaybackEngines/AndroidPlayer/OpenJDK
 
# build AAR file
gradle wrapper && ./gradlew assembleRelease

4. Create directory `<build-folder>/unityLibrary/build/unityLibrary`. Copy or move the following components into this directory:

<build-folder>/unityLibrary/build/outputs/aar/unityLibrary-release.aar
<build-folder>/unityLibrary/libs

5. Create file `<build-folder>/unityLibrary/build/unityLibrary/build.gradle` with the following content:


configurations.maybeCreate("default")
artifacts.add("default", file("unityLibrary-release.aar"))

Distribute files include the <build-folder>/unityLibrary/build/unityLibrary directory and its content

2. Prepare iOS Library (Unity Project)

1. Export iOS Project

2. Required Configurations

Change the Target Membership of the Data folder from Unity-iPhone to UnityFramework.
Change the access level of NativeCallProxy.h from Project to Public.
In Frameworks/Silver Tau/NSR/Runtime/Plugins/iOS, remove all Target Membership entries except UnityFramework (typically remove Unity-iPhone).
Remove bitcode from StcCorder.framework: bitcode_strip -r StcCorder.framework/StcCorder -o StcCorder.framework/StcCorder (ref: https://warchimede.com/posts/2024-10-08-how-to-remove-bitcode-from-framework/ )

3. Build framework and export XCFramework


xcodebuild archive -project "Unity-iPhone.xcodeproj" -scheme "UnityFramework"  -configuration Release  -destination generic/platform=iOS  -archivePath "build/app.xcarchive" CODE_SIGNING_ALLOWED=NO SKIP_INSTALL=NO BUILD_LIBRARY_FOR_DISTRIBUTION=YES
xcodebuild -create-xcframework -archive build/app.xcarchive -framework UnityFramework.framework -output build/UnityFramework.xcframework

Distribute files include the UnityFramework.framework and its contents