tiefen_space_app/utils/saveImage.js

import * as MediaLibrary from "expo-media-library";
import * as FileSystem from "expo-file-system";
import Toast from "react-native-toast-message";
import * as ImageManipulator from "expo-image-manipulator";

export default async function saveImage(uri) {
  const permission = await MediaLibrary.requestPermissionsAsync();
  if (permission.granted) {
    const timestamp = new Date().getTime();
    const fileUri = FileSystem.cacheDirectory + `${timestamp}.png`;
    try {
      const manipResult = await ImageManipulator.manipulateAsync(uri, [], {
        base64: true,
      });
      const base64Code = manipResult.base64;

      await FileSystem.writeAsStringAsync(fileUri, base64Code, {
        encoding: FileSystem.EncodingType.Base64,
      });

      await MediaLibrary.saveToLibraryAsync(fileUri);
      Toast.show({
        type: "success",
        text1: "已保存到相册",
        topOffset: 60,
      });
      return true;
    } catch (err) {
      console.error("FS Err: ", err);
      return false;
    }
  } else {
    Toast.show({
      type: "error",
      text1: "保存失败，请检查APP媒体权限",
      topOffset: 60,
    });
    return false;
  }
}