HarmonyOS 如何区分定位获取失败具体原因

// 校验应用是否被授予定位权限，可以通过调用checkAccessToken()方法来校验当前是否已经授权。 
async checkPermissions(): Promise<boolean> { 
  const permissions: Array<Permissions> = ['ohos.permission.LOCATION', 'ohos.permission.APPROXIMATELY_LOCATION']; 
  for (let permission of permissions) { 
  let grantStatus: abilityAccessCtrl.GrantStatus = await this.checkAccessToken(permission); 
  if (grantStatus === abilityAccessCtrl.GrantStatus.PERMISSION_GRANTED) { 
  return true; 
} 
} 
return false; 
} 
 
async checkAccessToken(permission: Permissions): Promise<abilityAccessCtrl.GrantStatus> { 
  let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager(); 
  let grantStatus: abilityAccessCtrl.GrantStatus = abilityAccessCtrl.GrantStatus.PERMISSION_DENIED; 
 
  // 获取应用程序的accessTokenID 
  let tokenId: number = 0; 
  try { 
  let bundleInfo: bundleManager.BundleInfo = await bundleManager.getBundleInfoForSelf(bundleManager.BundleFlag.GET_BUNDLE_INFO_WITH_APPLICATION); 
  let appInfo: bundleManager.ApplicationInfo = bundleInfo.appInfo; 
  tokenId = appInfo.accessTokenId; 
} catch (error) { 
  let err: BusinessError = error as BusinessError; 
  console.error(`Failed to get bundle info for self. Code is ${err.code}, message is ${err.message}`); 
} 
 
// 校验应用是否被授予权限 
try { 
  grantStatus = await atManager.checkAccessToken(tokenId, permission); 
} catch (error) { 
  let err: BusinessError = error as BusinessError; 
  console.error(`Failed to check access token. Code is ${err.code}, message is ${err.message}`); 
} 
 
return grantStatus; 
}