如何在react-native中将base64数据存储到设备内部/外部存储？

import { AsyncStorage, Platform } from 'react-native';
import RNFetchBlob from 'rn-fetch-blob';

const saveBase64ToStorage = async (base64Data, fileName, isExternal) => {
  try {
    const filePath = `${isExternal ? RNFetchBlob.fs.dirs.SDCardDir : RNFetchBlob.fs.dirs.DocumentDir}/${fileName}`;
    
    await RNFetchBlob.fs.writeFile(filePath, base64Data, 'base64');
    
    if (Platform.OS === 'android' && isExternal) {
      await RNFetchBlob.fs.scanFile([{ path: filePath, mime: 'application/octet-stream' }]);
    }
    
    return filePath;
  } catch (error) {
    console.log('Error saving base64 data:', error);
    return null;
  }
};

const base64Data = 'your_base64_data_here';
const fileName = 'your_file_name_here';
const isExternal = true; // 设置为true以保存到外部存储，设置为false以保存到内部存储

saveBase64ToStorage(base64Data, fileName, isExternal)
  .then(filePath => {
    if (filePath) {
      console.log('Base64 data saved successfully:', filePath);
    } else {
      console.log('Failed to save base64 data.');
    }
  });