HarmonyOS 鸿蒙Next中获取不到应用信息

HarmonyOS 鸿蒙Next中获取不到应用信息 获取不到应用版本号 调用封装的类方法:PackageUtils.getVersionName,获取返回的版本号是空的

import { bundleManager } from '@kit.AbilityKit';

export class PackageUtils{
  private static bundleInfo: bundleManager.BundleInfo |null = null;

  public static getVersionName(): Promise<string>{
    if(PackageUtils.bundleInfo==null){
      return new Promise((resolve,reject)=>{
        PackageUtils.getVersionNameImp();
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo.versionName);
        }else{
          resolve("");
        }
      });
    }else{
      return new Promise((resolve,reject)=>{
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo.versionName);
        }else{
          resolve("");
        }
      });
    }
  }

  public static getVersionCode(): Promise<number>{
    if(PackageUtils.bundleInfo==null){
      return new Promise((resolve,reject)=>{
        PackageUtils.getVersionNameImp();
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo.versionCode);
        }else{
          resolve(0);
        }
      });
    }else{
      return new Promise((resolve,reject)=>{
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo.versionCode);
        }else{
          resolve(0);
        }
      });
    }
  }

  public static getBundleInfo(): Promise<bundleManager.BundleInfo|null>{
    if(PackageUtils.bundleInfo==null){
      return new Promise((resolve,reject)=>{
        PackageUtils.getVersionNameImp();
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo);
        }else{
          resolve(null);
        }
      });
    }else{
      return new Promise((resolve,reject)=>{
        if(PackageUtils.bundleInfo!=null){
          resolve(PackageUtils.bundleInfo);
        }else{
          resolve(null);
        }
      });
    }
  }

  static async getVersionNameImp(){
    const bundleFlags = bundleManager.BundleFlag.GET_BUNDLE_INFO_WITH_APPLICATION;
    PackageUtils.bundleInfo = await bundleManager.getBundleInfoForSelf(bundleFlags);
  }
}