HarmonyOS 鸿蒙Next 文件拷贝

你好 1：无法访问别的app沙箱目录，例如获取相册的图片，拿到uri后，手动保存到自己沙箱路径。 2：设置好路径后，然后使用open，打开文件，即创建文件，然后往里面写入内容 3：可以通过fs.open，打开文件，然后往里面写入文件 4：参考demo:

import { BusinessError } from '@kit.BasicServicesKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import fileIo from '@ohos.file.fs';
let context = this.getContext()

@Entry
@Component
struct FilePage {

  build() {
    Column() {
      Button("相册选择").onClick(() => {
        try {
          let PhotoSelectOptions = new photoAccessHelper.PhotoSelectOptions();
          PhotoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE;
          PhotoSelectOptions.maxSelectNumber = 1;
          let photoPicker = new photoAccessHelper.PhotoViewPicker();
          photoPicker.select(PhotoSelectOptions).then(async (PhotoSelectResult: photoAccessHelper.PhotoSelectResult) => {
            console.error('PhotoViewPicker.select successfully, PhotoSelectResult uri: ' + JSON.stringify(PhotoSelectResult));
            let filePath =  context.cacheDir + '/test.png'
            let file = fileIo.openSync(PhotoSelectResult.photoUris[0], fileIo.OpenMode.READ_ONLY)
            let file2 = fileIo.openSync(filePath, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE)
            fileIo.copyFileSync(file.fd, file2.fd)
            fileIo.closeSync(file);
            fileIo.closeSync(file2);
          }).catch((err: BusinessError) => {
            console.error(`PhotoViewPicker.select failed with err: ${err.code}, ${err.message}`);
          });
        } catch (error) {
          let err: BusinessError = error as BusinessError;
          console.error(`PhotoViewPicker failed with err: ${err.code}, ${err.message}`);
        }
      })
    }
    .height('100%')
    .width('100%')
  }
}