如何在React Native中访问子视图？

import React, { useRef } from 'react';
import { View, TextInput, Button, Text } from 'react-native';

const ParentComponent = () => {
  const inputRef = useRef(null);

  const focusInput = () => {
    if (inputRef.current) {
      inputRef.current.focus();
    }
  };

  return (
    <View>
      <TextInput ref={inputRef} placeholder="Type here..." />
      <Button title="Focus the input" onPress={focusInput} />
    </View>
  );
};

export default ParentComponent;

import React, { useRef, useEffect } from 'react';
import { View, TextInput } from 'react-native';

const ParentComponent = () => {
  const inputRef = useRef(null);

  useEffect(() => {
    // 组件挂载后的逻辑
    return () => {
      // 组件卸载前的清理逻辑
    };
  }, []);

  const focusInput = () => {
    if (inputRef.current) {
      inputRef.current.focus();
    }
  };

  return (
    <View>
      <TextInput ref={inputRef} placeholder="Type here..." />
      <Button title="Focus the input" onPress={focusInput} />
    </View>
  );
};

export default ParentComponent;