HarmonyOS componentSnapshot页面截图保存图片到相册不完整

组件截图只能够截取组件大小的区域，如果组件的绘制超出了它的区域，或子组件的绘制超出了父组件的区域，这些在组件区域外绘制的内容不会在截图中呈现。兄弟节点堆叠在组件区域内，截图不会显示兄弟组件。可以在外层嵌套一个scroll来规避，参考示例：

import { componentSnapshot } from '@kit.ArkUI';
import { image } from '@kit.ImageKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import fs from '@ohos.file.fs';
import { BusinessError } from '@kit.BasicServicesKit';

@Entry
@Component
struct ComponentSnapshotPage {
  @State pixmap: image.PixelMap | null = null
  private arr: number[] = []
  @State centerIndex: number = 0

  aboutToAppear() {
    for (let i = 0; i < 10; i++) {
      this.arr.push(i)
    }
  }

  build() {
    Column() {
      SaveButton({ icon: SaveIconStyle.LINES, buttonType: ButtonType.Circle }).backgroundColor(Color.Gray)
        .onClick(async (event: ClickEvent, result: SaveButtonOnClickResult) => {
          if (result == SaveButtonOnClickResult.SUCCESS) {
            componentSnapshot.get("hello", async (error: Error, pixmap: image.PixelMap) => {
              this.pixmap = pixmap

              let packOpts: image.PackingOption = { format: "image/jpeg", quality: 100 };
              const imagePackerApi = image.createImagePacker();
              imagePackerApi.packing(pixmap, packOpts).then(async (buffer: ArrayBuffer) => {
                try {
                  const context = getContext(this)
                  let helper = photoAccessHelper.getPhotoAccessHelper(context)
                  let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg')
                  let file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE)
                  await fs.write(file.fd, buffer);
                  // 关闭文件
                  await fs.close(file.fd);
                } catch (error) {
                  console.error("error is " + JSON.stringify(error))
                }
              }).catch((error: BusinessError) => {
                console.error('Failed to pack the image. And the error is: ' + error);
              })
            })
          }
        })

      Scroll() {
        List() {
          ForEach(this.arr, (item: number) => {
            ListItem() {
              Text('' + item)
                .width('100%').height(100).fontSize(16)
            }

          }, (item: number) => JSON.stringify(item))
        }.width('100%').id('hello').backgroundColor(Color.White)
      }
    }
    .height('100%')
    .width('100%')
  }
}