java - 统一: Call Android Kotlin Function Inside Companion Object from Unity

Question

我是一名本地开发人员，并且是 Unity 的新手。我试图通过在 Kotlin 中编码，然后将我的代码用作 Unity 中的插件来发挥我的优势。我遇到的一个问题是我无法弄清楚如何引用伴随对象内部的函数。
这是我的 Kotlin 类(class)

class MyAnalytics internal constructor(
    private val MyAnalyticsConfiguration: MyAnalyticsConfiguration
) : MyAnalyticsLogger {

    .
    .
    .

    override fun logEvent(eventRequest: Event?) {
        // some code in here
    }

    companion object {

        @JvmStatic
        fun factory(
            context: Context,
            MyAnalyticsConfiguration: MyAnalyticsConfiguration = MyAnalyticsConfiguration()
        ) : MyAnalytics {
            val eventExecutor = MyWorkManager(
                workManager = WorkManager.getInstance(context.applicationContext),
                MyAnalyticsConfiguration = MyAnalyticsConfiguration
            )
            return MyAnalytics(
                MyAnalyticsConfiguration
            )
        }
    }
}

我希望能够访问 factory我的 Unity 代码中的函数。
在 Kotlin 我可以这样做，

MyAnalytics.factory(
      context = requireActivity()
)

但是我怎样才能在 Unity 中做同样的事情呢？这是我尝试过的。

AndroidJavaClass UnityPlayerClass = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
AndroidJavaObject UnityPlayerActivity = UnityPlayerClass.GetStatic<AndroidJavaObject>("currentActivity");
AndroidJavaObject myAnalytics = new AndroidJavaObject("com.test.analytics.MyAnalytics");
AndroidJavaObject analyticsObject = myAnalytics.Call<AndroidJavaObject>("factory", UnityPlayerActivity); //Also tried with 'CallStatic'; no result, same error

我收到的错误是，

AndroidJavaException: java.lang.NoSuchMethodError: no static method with name='factory' signature='(Landroid.app.Application;)Ljava/lang/Object;' in class Ljava.lang.Object;12-10 14:00:21.883 13537 13674 E Unity : java.lang.NoSuchMethodError: no static method with name='factory' signature='(Landroid.app.Application;)Ljava/lang/Object;' in class Ljava.lang.Object;12-10 14:00:21.883 13537 13674 E Unity : at com.unity3d.player.ReflectionHelper.getMethodID(Unknown Source:162)12-10 14:00:21.883 13537 13674 E Unity : at com.unity3d.player.UnityPlayer.nativeRender(Native Method)12-10 14:00:21.883 13537 13674 E Unity : at com.unity3d.player.UnityPlayer.access$300(Unknown Source:0)12-10 14:00:21.883 13537 13674 E Unity : at com.unity3d.player.UnityPlayer$e$1.handleMessage(Unknown Source:95)12-10 14:00:21.883 13537 13674 E Unity : at android.os.Handler.dispatchMessage(Handler.java:103)12-10 14:00:21.883 13537 13674 E Unity : at android.os.Looper.loop(Looper.java:214)12-10 14:00:21.883 13537 13674 E Unity : at com.unity3d.player.UnityPlayer$e.run(Unknown Source:20)

Answer 1

为了了解您的实现实际上有什么问题，您需要反编译您的 Kotlin代码到 Java编码并实现 Unity部分基于 Java代码，而不是 Kotlin .
让我们举一个简单的例子 Kotlin代码，它将打印日志，仅此而已:

class MyKotlinClass(val name: String = "DEFAULT NAME") {
    fun callNormalFunc() {
        Log.d("UNITY", "callNormalFunc from Kotlin code")
    }
    companion object {
        @JvmStatic
        fun callStaticCompanionFunc(): MyKotlinClass {
            Log.d("UNITY", "callStaticCompanionFunc from Kotlin code")
            return MyKotlinClass("NEW NAME")
        }
    }
}

而反编译的 Java代码如下所示:

public final class MyKotlinClass {
   @NotNull
   private final String name;
   @NotNull
   public static final MyKotlinClass.Companion Companion = new MyKotlinClass.Companion((DefaultConstructorMarker)null);

   public final void callNormalFunc() {
      Log.d("UNITY", "callNormalFunc from Kotlin code");
   }

   @NotNull
   public final String getName() {
      return this.name;
   }

   public MyKotlinClass(@NotNull String name) {
      Intrinsics.checkNotNullParameter(name, "name");
      super();
      this.name = name;
   }

   // $FF: synthetic method
   public MyKotlinClass(String var1, int var2, DefaultConstructorMarker var3) {
      if ((var2 & 1) != 0) {
         var1 = "DEFAULT NAME";
      }

      this(var1);
   }

   public MyKotlinClass() {
      this((String)null, 1, (DefaultConstructorMarker)null);
   }

   @JvmStatic
   @NotNull
   public static final MyKotlinClass callStaticCompanionFunc() {
      return Companion.callStaticCompanionFunc();
   }

   public static final class Companion {
      @JvmStatic
      @NotNull
      public final MyKotlinClass callStaticCompanionFunc() {
         Log.d("UNITY", "callStaticCompanionFunc from Kotlin code");
         return new MyKotlinClass("NEW NAME");
      }

      private Companion() {
      }

      // $FF: synthetic method
      public Companion(DefaultConstructorMarker $constructor_marker) {
         this();
      }
   }
}

从反编译的代码中可以看出，实际上我们可以调用标记为 @JvmStatic的函数。有两种方式。首先直接来自我们的对象，然后使用 Companion目的。
使用此调用的 Unity 代码如下所示:

public class KotlinCallScript : MonoBehaviour {

    private AndroidJavaObject _object;
    private AndroidJavaClass _staticClass;
    // Start is called before the first frame update
    private void Start () {
        _object = new AndroidJavaObject ("com.hardartcore.kotlin.MyKotlinClass");
        _staticClass = new AndroidJavaClass ("com.hardartcore.kotlin.MyKotlinClass");
        var defaultName = _object.Call<string> ("getName");
        Debug.Log ("START GET DEFAUL NAME: " + defaultName);
    }

    public void CallNormalFunction () {
        _object.Call ("callNormalFunc");
    }

    public void CallStaticFunction () {
        var companionObject = _staticClass.GetStatic<AndroidJavaObject> ("Companion");
        var newName = companionObject.Call<AndroidJavaObject> ("callStaticCompanionFunc").Call<string> ("getName");
        Debug.Log ("CALL STATIC FUNCTION NEW NAME: " + newName);
    }

    public void CallSecondWay () {
        var kotlinObject = _object.CallStatic<AndroidJavaObject> ("callStaticCompanionFunc");
        var newName = kotlinObject.Call<string> ("getName");
        Debug.Log ("CALL SECOND WAY NEW NAME: " + newName);
    }

}

这取决于您喜欢哪种方式。
我的建议是查看您反编译的 Java 代码，将其发布在这里，以便我们了解它为什么不起作用。