HarmonyOS Web组件打开pdf的页面

import { http } from '@kit.NetworkKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { common } from '@kit.AbilityKit';
import fs, { ReadOptions, WriteOptions } from '@ohos.file.fs';
import { filePreview } from '@kit.PreviewKit';
import { pdfService } from '@kit.PDFKit';
import web_webview from '@ohos.web.webview'
import { promptAction } from '@kit.ArkUI';

@Entry
@Component
struct Index {
  context = getContext(this) as common.UIAbilityContext;
  controller: web_webview.WebviewController = new web_webview.WebviewController();

  aboutToAppear(): void {

  }

  build() {

    Column() {
      Button("下载pdf").onClick(() => {
        // 每一个httpRequest对应一个HTTP请求任务，不可复用
        let httpRequest = http.createHttp();
        httpRequest.requestInStream('xxx.pdf', {
          extraData: http.HttpDataType.ARRAY_BUFFER
        })

        // 用于订阅HTTP流式响应数据接收事件
        let res = new ArrayBuffer(0);
        httpRequest.on('dataReceive', (data: ArrayBuffer) => {
          const newRes = new ArrayBuffer(res.byteLength + data.byteLength);
          const resView = new Uint8Array(newRes);
          resView.set(new Uint8Array(res));
          resView.set(new Uint8Array(data), res.byteLength);
          res = newRes;
          console.info('res length: ' + res.byteLength);
        });
        // 用于订阅HTTP流式响应数据接收完毕事件
        httpRequest.on('dataEnd', () => {
          console.info('No more data in response, data receive end');
          promptAction.showToast({
            message: "下载成功"
          })
          let srcFile = fs.openSync(this.context.filesDir + '/test.pdf', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
          fs.write(srcFile.fd, res)
        });
      })
      Button("加载pdf").onClick(() => {

        const filePath = `${this.context.filesDir}/test.pdf`
        let document: pdfService.PdfDocument = new pdfService.PdfDocument();
        document.loadDocument(filePath, '', (progress: number) => {
          return progress;
        });
        this.controller.loadUrl(`file://${this.context.filesDir}/test.pdf#scrollbars=0&toolbar=0&statusbar=0`)
      })
      Web({
        src: `www.huawei.com`,
        controller: this.controller
      }).domStorageAccess(true)
    }
  }
}