Building an Augmented Reality App with React Native

import React, { useRef, useEffect } from 'react';
import { StyleSheet, Text, View } from 'react-native';
import { ARKit, ARFaceAnchor } from 'react-native-arkit';
 
export default function App() {
  const arkitRef = useRef();
 
  useEffect(() => {
    const sub = arkitRef.current.arkitEventEmitter.addListener(
      'ARFaceAnchorDidUpdate',
      (event) => {
        // 处理面部跟踪数据
        console.log(event.faceAnchor);
      }
    );
    return () => sub.remove();
  }, []);
 
  return (
    <View style={styles.container}>
      <ARKit
        ref={arkitRef}
        style={styles.arView}
        planeDetection={ARKit.ARPlaneDetectionTypes.Horizontal}
      />
    </View>
  );
}
 
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
  arView: {
    width: '100%',
    height: '100%',
    position: 'absolute',
  },
});

这段代码展示了如何在React Native应用中集成ARKit，并监听面部跟踪事件。使用了React的hook（useRef和useEffect）来管理组件的生命周期并处理事件监听。这是目前在React Native中实现AR功能的一种流行且推荐的方法。