HarmonyOS 图片选择器的使用，photoAccessHelper.PhotoViewPicker和picker.PhotoViewPicker的区别是什么？

针对该问题进行解答：

1、photoAccessHelper.PhotoViewPicker和picker.PhotoViewPicker的区别：photoAccessHelper.PhotoViewPicker支持开发者对收藏夹、视频相册、截屏和录屏相册进行相关操作，用于操作系统相册资源；而picker.PhotoViewPicker则是可以用来访问、保存“公共目录”的图片或视频文件

2、ohos.file.fs提供基础文件操作能力，不需要额外申请权限。但需要注意的是使用fs只能操作文件应用沙箱路径path，例如fs.open无法打开photoViewPicker选择文件的uri，需要进行额外操作，示例核心代码如下：

//缓存目录 
let context = getContext(this) as common.UIAbilityContext;
let cacheDir = context.cacheDir;
photoViewPicker.select(photoSelectOptions).then(async (photoSelectResult: picker.PhotoSelectResult) => {
  uris = photoSelectResult.photoUris;
  console.info('photoViewPicker.select to file succeed and uris are:' + uris);
  let uri: string = uris[0];
  let file = fs.openSync(uri,
    fs.OpenMode.READ_ONLY);
  // 复制文件到缓存目录下 
  fs.copyFileSync(file.fd, cacheDir + '/test.jpeg')
  fs.stat(cacheDir + '/test.jpeg').then((stat: fs.Stat) => {
    console.info("get file info succeed, the size of file is " + stat.size);
  }).catch((err: BusinessError) => {
    console.error("get file info failed with error message: " + err.message + ", error code: " + err.code);
  });
}).catch((err: BusinessError) => {
  console.error(`Invoke photoViewPicker.select failed, code is ${err.code}, message is ${err.message}`);
}) 

3、使用到picker编辑图片能力时，建议使用new picker.PhotoViewPicker() 来生成 photoPicker 对象，示例demo：

import { photoAccessHelper } from '@kit.MediaLibraryKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import picker from '@ohos.file.picker';

@Entry
@Component
struct PhotoPickerPage2 {
  @State img: string = ''
  aboutToDisappear() {
  }
  build() {
    Column() {
      Button("Button")
        .onClick(() => {
          let photoPicker = new picker.PhotoViewPicker();
          photoPicker.select(
            {MIMEType: 'image/*', maxSelectNumber: 1, isPhotoTakingSupported: true, isEditSupported: true, isSearchSupported: false} as photoAccessHelper.PhotoSelectOptions
          ).then((res) => {
            if (res.photoUris.length > 0) {
              this.img = res.photoUris[0]
            }
          }).catch((err: BusinessError) => {
            hilog.info(1, "hilog",'select error: ' + err.code + ' ' + err.message)
          })
        })
      Image(this.img)
    }.width('100%').margin({ top: 5 })

  }
}

photoAccessHelper更建议用作选择图片