【HarmonyOS NEXT】实现保存base64图片到图库

上篇文章介绍了HarmonyOS NEXT如何保存base64文件到download目录下，本次介绍如何保存base64图片到图库，网络图片保存方式大同小异，先下载图片，然后再保存

phAccessHelper.showAssetsCreationDialog

参考官方文档’

@ohos.file.photoAccessHelper (相册管理模块)-ArkTS API-Media Library Kit（媒体文件管理服务）-媒体 - 华为HarmonyOS开发者 (huawei.com)

完整代码如下

//模拟数据
 param ="{\"dataBase64\":\"data:image/png;base64,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\",\"fileType\":\"png\",\"fileName\":\"\"}"
    if (StringUtils.isStrNotBlank(param)) {
      const h5CallBackBean: H5CallBackBean | null = JSONUtil.jsonToBean<H5CallBackBean>(H5CallBackBean, param)
//保存图片
          let context = getContext(this);
          let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(context);
          const fileBase64 = h5CallBackBean.dataBase64
          if (StringUtils.isStrNotBlank(fileBase64)) {
            const base64: string = fileBase64.split(",")[1]
            let applicationContext = getContext().getApplicationContext()
            const numTemp: number = DateUtil.getTodayTime()
            let filePath = applicationContext.filesDir + '/' + numTemp + "." + h5CallBackBean.fileType
            if (UiUtils.saveBase64File(base64, filePath)) {
              try {
                // 获取需要保存到媒体库的位于应用沙箱的图片/视频uri
                let srcFileUris: Array<string> = [
                  fileUri.getUriFromPath(filePath)
                ];
                let photoCreationConfigs: Array<photoAccessHelper.PhotoCreationConfig> = [
                  {
                    fileNameExtension: 'jpg',
                    photoType: photoAccessHelper.PhotoType.IMAGE,
                    subtype: photoAccessHelper.PhotoSubtype.DEFAULT, // 可选
                  }
                ];
                let desFileUris: Array<string> =
                  await phAccessHelper.showAssetsCreationDialog(srcFileUris, photoCreationConfigs);
                console.info('showAssetsCreationDialog success, data is ' + desFileUris);
                if (desFileUris.length > 0) {
                  FileUtil.copyFileSync(filePath,new fileUri.FileUri(desFileUris[0]).path)
                  try {
                    console.log(`context.fileDir ===> ${context.filesDir}`)
                    let srcFile: fs.File = fs.openSync(fileUri.getUriFromPath(filePath), fs.OpenMode.READ_ONLY);
                    let targetFile: fs.File = await fs.open(desFileUris[0], 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);
                    ToastUtil.showToast("保存成功")
                    if (FileUtil.accessSync(filePath)) {
                      FileUtil.unlink(filePath)
                    }
                  } catch (error) {
                    console.error(`createAssetByIo :: error , msg is ${error} `);
                  }

                } else {
                  ToastUtil.showToast("您拒绝了保存图片")
                }


              } catch (err) {
                console.error('showAssetsCreationDialog failed, errCode is ' + err.code + ', errMsg is ' + err.message);
              }
            } else {
              ToastUtil.showToast("保存失败,请稍后重试")
            }

          }


        }



}

其中用到的第三方依赖和上篇文章一致

参考：HarmonyNext保存Base64文件到Download下-CSDN博客

效果如下

【其它问题】
关于授权窗，没显示图片缩略图的问题，官方给的答复是下载最新版本的IDE