RvUtil.cs

public class RvUtil
    {
        public RvUtil (RecyclerView rv)
        {
            recyclerView = rv;
        }

        RecyclerView recyclerView;

        IntPtr id_setNestedScrollingEnabled;
        IntPtr id_isNestedScrollingEnabled;

        public IntPtr baseHandle
        {
            get { return recyclerView.Handle; }
        }

        public IntPtr ThresholdClass
        {
            get {
                var t = typeof(RecyclerView);
                var m = t.GetProperty("ThresholdClass", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
                return (IntPtr)m.GetValue(recyclerView);
            }
        }

        public Type ThresholdType {
            get {
                var t = typeof(RecyclerView);
                var m = t.GetProperty("ThresholdType", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
                return (Type)m.GetValue(recyclerView);
            }
        }

        public IntPtr class_ref
        {
            get {
                var t = typeof(RecyclerView);
                var m = t.GetProperty("class_ref", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic);
                return (IntPtr)m.GetValue(recyclerView);
            }
        }

        [Register("isNestedScrollingEnabled", "()Z", "GetIsNestedScrollingEnabledHandler")]
        public unsafe virtual bool IsNestedScrollingEnabled ()
        {
            if (id_isNestedScrollingEnabled == IntPtr.Zero) {
                id_isNestedScrollingEnabled = JNIEnv.GetMethodID(class_ref, "isNestedScrollingEnabled", "()Z");
            }
            if (recyclerView.GetType().BaseType == ThresholdType) {
                return JNIEnv.CallBooleanMethod(baseHandle, id_isNestedScrollingEnabled);
            }
            return JNIEnv.CallNonvirtualBooleanMethod(baseHandle, ThresholdClass, JNIEnv.GetMethodID(ThresholdClass, "isNestedScrollingEnabled", "()Z"));
        }

        [Register("setNestedScrollingEnabled", "(Z)V", "GetSetNestedScrollingEnabledHandler")]
        public unsafe virtual void SetNestedScrollingEnabled(bool value)
        {
            if (id_setNestedScrollingEnabled == IntPtr.Zero) {
                id_setNestedScrollingEnabled = JNIEnv.GetMethodID(class_ref, "setNestedScrollingEnabled", "(Z)V");
            }
            JValue* ptr = stackalloc JValue[1];
            *ptr = new JValue(value);
            if (recyclerView.GetType().BaseType == ThresholdType) {
                JNIEnv.CallVoidMethod(baseHandle, id_setNestedScrollingEnabled, ptr);
                return;
            }
            JNIEnv.CallNonvirtualVoidMethod(baseHandle, ThresholdClass, JNIEnv.GetMethodID(ThresholdClass, "setNestedScrollingEnabled", "(Z)V"), ptr);
        }
    }