鸿蒙开发 数据持久化，卸载应用，数据依然存在

HarmonyOS NEXT api12
@ohos.security.asset (关键资产存储服务)

import { asset } from '@kit.AssetStoreKit';
import { buffer } from '@kit.ArkTS';
import { BusinessError } from '@kit.BasicServicesKit';
import { YXUniversalTool } from "../YXUniversalTool";

export class YXAssetStore {

  public static strToUint8Array(src: string, encoding: buffer.BufferEncoding = 'utf-8'): Uint8Array {
    return YXUniversalTool.strToUint8Array(src,encoding);
  }

  public static unit8ArrayToStr(src: Uint8Array, encoding: buffer.BufferEncoding = 'utf-8'): string {
    return YXUniversalTool.unit8ArrayToStr(src,encoding);
  }

  static setSync(key: string, value: string) {

    let attr: asset.AssetMap = new Map();
    attr.set(asset.Tag.ALIAS, YXAssetStore.strToUint8Array(key));
    attr.set(asset.Tag.SECRET, YXAssetStore.strToUint8Array(value));
    attr.set(asset.Tag.ACCESSIBILITY,asset.Accessibility.DEVICE_POWERED_ON);
    attr.set(asset.Tag.REQUIRE_PASSWORD_SET,false);
    attr.set(asset.Tag.AUTH_TYPE,asset.AuthType.NONE);
    attr.set(asset.Tag.SYNC_TYPE, asset.SyncType.THIS_DEVICE);
    attr.set(asset.Tag.IS_PERSISTENT,true);
    attr.set(asset.Tag.CONFLICT_RESOLUTION, asset.ConflictResolution.OVERWRITE);
    try {
      asset.addSync(attr);
    } catch (err) {
      let error = err as BusinessError;
      console.log(`AssetStore-set-异常 ~ code: ${error.code} -·- message: ${error.message}`);
    }
  }

  static getSync(key: string): string {

    let attr: asset.AssetMap = new Map();
    attr.set(asset.Tag.ALIAS, YXAssetStore.strToUint8Array(key));
    attr.set(asset.Tag.RETURN_TYPE, asset.ReturnType.ALL);
    attr.set(asset.Tag.ACCESSIBILITY,asset.Accessibility.DEVICE_POWERED_ON);
    attr.set(asset.Tag.REQUIRE_PASSWORD_SET,false);
    attr.set(asset.Tag.AUTH_TYPE,asset.AuthType.NONE);

    try {
      let res = asset.querySync(attr);
      if (res.length == 0) {
        return "";
      }

      let map: asset.AssetMap = res[0];
      let arr = map.get(asset.Tag.SECRET) as Uint8Array;
      if (arr) {
        let value = YXAssetStore.unit8ArrayToStr(arr);
        return value;
      }
    } catch (err) {
      let error = err as BusinessError;
      console.log(`AssetStore-set-异常 ~ code: ${error.code} -·- message: ${error.message}`);
    }
    return "";
  }

  static removeSync(key: string) {

    let attr: asset.AssetMap = new Map();
    attr.set(asset.Tag.ALIAS, YXAssetStore.strToUint8Array(key));

    try {
      asset.removeSync(attr);
    } catch (err) {
      let error = err as BusinessError;
      console.log(`AssetStore-set-异常 ~ code: ${error.code} -·- message: ${error.message}`);
    }
  }
}