HarmonyOS 鸿蒙Next RN端react-native-image-picker获取图片只能获取uri无法获取base64

可以参考链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-faqs-V5/faqs-image-kit-0000001816452293-V5#section871313119219

import { image } from '@kit.ImageKit';

import { buffer } from '@kit.ArkTS';

@Entry

@Component

struct Index {

  @State message: string = 'PixelMapToBase64';

  @State base64: string = '';

  build() {

    Row() {

      Column() {

        Text(this.message)

          .fontSize(50)

          .fontWeight(FontWeight.Bold)

          .onClick(async () => {

            let resourceManager = getContext(this).resourceManager

            let imageArray = await resourceManager.getMediaContent($r('app.media.sample7'));

            let pixelBuffer = new Uint8Array(imageArray).buffer as Object as ArrayBuffer;

            let imageResource = image.createImageSource(pixelBuffer);

            let opts: image.DecodingOptions = { editable: true }

            let pixelMap = await imageResource.createPixelMap(opts);

            // 转换成base64

            const imagePackerApi: image.ImagePacker = image.createImagePacker();

            let packOpts: image.PackingOption = { format: 'image/jpeg', quality: 100 };

            imagePackerApi.packing(pixelMap, packOpts).then((data: ArrayBuffer) => {

              let buf: buffer.Buffer = buffer.from(data);

              this.base64 = 'data:image/jpeg;base64,' + buf.toString('base64', 0, buf.length);

              console.info('base64: ' + this.base64);

            })

          })

        Image(this.base64)

          .width(200).height(200).margin(15)

      }

      .width('100%')

    }

    .height('100%')

  }

}