【HarmonyOS NEXT】实现网络图片保存到手机相册

【问题描述】
给定一个网络图片的地址，实现将图片保存到手机相册

【API】

phAccessHelper.showAssetsCreationDialog

【官方文档】
https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-photoaccesshelper-V5#showassetscreationdialog12

【完整代码】

import { http } from '@kit.NetworkKit';
import { BusinessError } from '@kit.BasicServicesKit';
import util from '@ohos.util';
import { fileUri } from '@kit.CoreFileKit';
import fs, { ReadOptions } from '@ohos.file.fs';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import { dataSharePredicates } from '@kit.ArkData';
import { promptAction } from '@kit.ArkUI';@Entry
@Component
struct SaveAlbum {@State message: string = 'Hello World';url1: string = "https://img20.360buyimg.com/img/jfs/t1/241153/31/4968/64736/65e53e56Fd3868b6e/b595d41ca8447ea4.jpg";url2: string ="https://upfile-drcn.platform.hicloud.com/ptTJ5B1eJ6k-d45UmOTF0Q.FYlVoBLGO3P9jZfjPUtqh2Cry9mQBzJButWu-okMhg2Xsd4zaoBTVAAsA08DPk1Vn7VFa1Mpl1Dp112CNKhEBjd4a9kP2NCKrQUpgq0HP_E3uqofnQ.6099200.png";build() {Column({ space: 30 }) {Text('保存到相册').fontSize(30)Column() {Text(this.url1)Button("保存").onClick(() => {this.downloadAndSave(this.url1)})}.margin({ top: 15, bottom: 15 })Column() {Text(this.url2)Button("保存").onClick(() => {this.downloadAndSave(this.url2);})}.margin({ top: 15, bottom: 15 })}.justifyContent(FlexAlign.Center).alignItems(HorizontalAlign.Center).height('100%').width('100%')}downloadAndSave(url: string) {const arr = url.split('.')const type = arr[arr.length -1]httpDownload(url, type).then((result: DownloadResult) => {if (result.isSuccess) {promptAction.showToast({ message: "下载成功" })} else {console.error("失败：" + result.msg);promptAction.showToast({ message: "下载失败❌，请查看日志" })}})}
}interface DownloadResult {isSuccess: boolean,msg: string
}async function httpDownload(imgUrl: string, imgType: string): Promise<DownloadResult> {return new Promise((resolve, reject) => {http.createHttp().request(imgUrl, async (error: BusinessError, data: http.HttpResponse) => { // 下载失败if (error) {return resolve({ isSuccess: false, msg: "下载失败" });} // 数据格式不正确if ((data.result instanceof ArrayBuffer) == false) {return resolve({ isSuccess: false, msg: "图片保存失败：数据流不支持" });} // 保存到Cache目录下let imageBuffer: ArrayBuffer = data.result as ArrayBuffer;const newFileName = util.generateRandomUUID() + "." + imgType;const newFilePath = getContext().cacheDir + "/" + newFileName;const newFileUri = fileUri.getUriFromPath(newFilePath);let file: fs.File = await fs.open(newFileUri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);await fs.write(file.fd, imageBuffer);await fs.close(file);console.info("文件路径：" + newFileUri); // 保存成功 // resultData.status = 3; // return resolve(resultData);saveImageToAsset(newFileUri, imgType).then(() => { // 保存成功return resolve({ isSuccess: true, msg: "保存成功" });}).catch((error: Error) => { // 保存失败return resolve({ isSuccess: false, msg: "保存失败:" + error.message });});});})
}async function saveImageToAsset(uri: string, nameExtension: string): Promise<void> {console.info('ShowAssetsCreationDialogDemo: ' + uri);try {let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(getContext()); // 获取需要保存到媒体库的位于应用沙箱的图片/视频urilet srcFileUris: Array<string> = [uri];let photoCreationConfigs: Array<photoAccessHelper.PhotoCreationConfig> = [{title: 'test2', // 可选fileNameExtension: nameExtension,photoType: photoAccessHelper.PhotoType.IMAGE, // 可选，支持：普通图片、动态图片subtype: photoAccessHelper.PhotoSubtype.DEFAULT,}];let desFileUris: Array<string> = await phAccessHelper.showAssetsCreationDialog(srcFileUris, photoCreationConfigs);console.info('showAssetsCreationDialog success, data is ' + desFileUris);if (desFileUris.length == 0) { // 用户拒绝保存throw (new Error("用户拒绝保存"))}await createAssetByIo(uri, desFileUris[0]);return Promise.resolve();} catch (err) {console.error('showAssetsCreationDialog failed, errCode is ' + err.code + ', errMsg is ' + err.message);return Promise.reject(err);}
}let context = getContext(this);
const createAssetByIo = async (sourceFilePath: string, targetFilePath: string) => {try {console.log(`context.fileDir ===> ${context.filesDir}`)let srcFile: fs.File = fs.openSync(sourceFilePath, fs.OpenMode.READ_ONLY);let targetFile: fs.File = await fs.open(targetFilePath, fs.OpenMode.READ_WRITE);let bufSize = 14096;let readSize = 0;let buf = new ArrayBuffer(bufSize);let readOptions: ReadOptions = { offset: readSize, length: bufSize };let readLen = fs.readSync(srcFile.fd, buf, readOptions);while (readLen > 0) {readSize += readLen;fs.writeSync(targetFile.fd, buf, { length: readLen });readOptions.offset = readSize;readLen = fs.readSync(srcFile.fd, buf, readOptions);}fs.closeSync(srcFile);fs.closeSync(targetFile);} catch (error) {console.error(`createAssetByIo :: error , msg is ${error} `);}
}