在获取数据之前，如何在react native中使用activityIndicator？

import React, { useState, useEffect } from 'react';
import { View, ActivityIndicator, StyleSheet } from 'react-native';

const App = () => {
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    // 模拟数据加载
    setTimeout(() => {
      setLoading(false);
    }, 2000);
  }, []);

  if (loading) {
    return (
      <View style={styles.container}>
        <ActivityIndicator size="large" color="#0000ff" />
      </View>
    );
  }

  return (
    <View style={styles.container}>
      {/* 这里放置加载完成后的内容 */}
      <Text>数据加载完成！</Text>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
});

export default App;