HarmonyOS 鸿蒙Next 获取相册图片大小以及视频时长

可以参考如下demo：

import photoAccessHelper from '[@ohos](/user/ohos).file.photoAccessHelper';
import { BusinessError } from '[@ohos](/user/ohos).base';
import dataSharePredicates from '[@ohos](/user/ohos).data.dataSharePredicates';
import { picker } from '[@kit](/user/kit).CoreFileKit';

[@Entry](/user/Entry)
[@Component](/user/Component)
struct Index {
// 定义一个uri数组，用于接收PhotoViewPicker选择图片返回的uri
[@State](/user/State) uris: Array<string> = [];
context = getContext(this);

// 调用PhotoViewPicker.select选择图片
async photoPickerGetUri() {
try {
// let PhotoSelectOptions = new picker.PhotoSelectOptions();
// PhotoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE;
// PhotoSelectOptions.maxSelectNumber = 1;
let photoViewPicker = new picker.PhotoViewPicker();
photoViewPicker.select().then(async (PhotoSelectResult: picker.PhotoSelectResult) => {
console.info('PhotoViewPicker.select successfully, PhotoSelectResult uri: ' +
JSON.stringify(PhotoSelectResult));
this.uris = PhotoSelectResult.photoUris;
this.uriGetAssets()
}).catch((err: BusinessError) => {
console.error('PhotoViewPicker.select failed with err: ' + JSON.stringify(err));
});
} catch (error) {
let err: BusinessError = error as BusinessError;
console.error('PhotoViewPicker failed with err: ' + JSON.stringify(err));
}
}

async uriGetAssets() {
try {
let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(this.context);
let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
// 配置查询条件，使用PhotoViewPicker选择图片返回的uri进行查询
predicates.equalTo('uri', this.uris[0]);
let fetchOption: photoAccessHelper.FetchOptions = {
fetchColumns: [photoAccessHelper.PhotoKeys.WIDTH, photoAccessHelper.PhotoKeys.HEIGHT,
photoAccessHelper.PhotoKeys.TITLE, photoAccessHelper.PhotoKeys.SIZE, photoAccessHelper.PhotoKeys.DURATION],
predicates: predicates
};
let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> =
await phAccessHelper.getAssets(fetchOption);
// 得到uri对应的PhotoAsset对象，读取文件的部分信息
const asset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
console.info('asset displayName: ', asset.displayName);
console.info('asset uri: ', asset.uri);
console.info('asset photoType: ', asset.photoType);
console.info('asset width: ', asset.get(photoAccessHelper.PhotoKeys.WIDTH));
console.info('asset height: ', asset.get(photoAccessHelper.PhotoKeys.HEIGHT));
console.info('asset SIZE: ' + asset.get(photoAccessHelper.PhotoKeys.SIZE));
console.info('asset DURATION: ' + asset.get(photoAccessHelper.PhotoKeys.DURATION));
// 获取缩略图
asset.getThumbnail((err, pixelMap) => {
if (err == undefined) {
console.info('getThumbnail successful ' + JSON.stringify(pixelMap));
} else {
console.error('getThumbnail fail', err);
}
});
} catch (error) {
console.error('uriGetAssets failed with err: ' + JSON.stringify(error));
}
}

build() {
Button('获取文件大小').width(100).height(100)
.onClick(() => {
this.photoPickerGetUri()
})
}
}