HarmonyOS 获取网络图片高度

可以参考以下demo：

import http from '@ohos.net.http';
import image from '@ohos.multimedia.image';
import { BusinessError } from '@ohos.base';

@Entry
@Component
struct ImageToPixelMap {
  @State image: PixelMap | undefined = undefined;
  private imageWith: number = 0;
  private imageHeight: Length = 100;

  aboutToAppear(): void {
    this.httpRequest()
  }

  build() {
    Column() {
      Image(this.image)
        .height(this.imageHeight).width(this.imageWith)

    }.width('100%').height('100%')
  }

  httpRequest() {
    http.createHttp().request(
      "https://xxx.jpg",
      (error: BusinessError, data: http.HttpResponse) => {
        if (error) {
          console.error(`http reqeust failed with. Code: ${error.code}, message: ${error.message}`);
        } else {
          console.error('http reqeust success.');
          let imageData: ArrayBuffer = data.result as ArrayBuffer;
          let imageSource: image.ImageSource = image.createImageSource(imageData);
          console.error(`http reqeust size = ${imageData.byteLength}`);

          let opts: image.DecodingOptions = { editable: true }
          let pixelMap: image.PixelMap = imageSource.createPixelMapSync(opts);
          pixelMap.getImageInfo().then((imageInfo: image.ImageInfo) => {
            if (imageInfo == undefined) {
              console.error("Failed to obtain the image pixel map information.");
            }
            this.imageWith = imageInfo.size.width;
            this.imageHeight = imageInfo.size.height;
            console.log("Succeeded in obtaining the image pixel map information.", this.imageWith,
              this.imageHeight);
          })

          class tmp {
            height: number = 100
            width: number = 100
          }

          let options: Record<string, number | boolean | tmp> = {
            'alphaType': 0, // 透明度
            'editable': false, // 是否可编辑
            'pixelFormat': 3, // 像素格式
            'scaleMode': 1, // 缩略值
            'size': { height: 100, width: 100 }
          } // 创建图片大小
          imageSource.createPixelMap(options).then((pixelMap: PixelMap) => {
            this.image = pixelMap
          })
        }
      }
    )
  }
}