HarmonyOS如何获取截屏图片

async example66() {
console.info('getAssets');
let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
let fetchOptions: photoAccessHelper.FetchOptions = {
fetchColumns: [],
predicates: predicates
};

phAccessHelper.getAssets(fetchOptions, async (err, fetchResult) => {
if (fetchResult !== undefined) {
console.info('fetchResult success');
let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
if (photoAsset !== undefined) {
console.info('photoAsset.displayName : ' + photoAsset.displayName);
}
} else {
console.error(`fetchResult fail with error: ${err.code}, ${err.message}`);
}
});
}