HarmonyOS 鸿蒙Next中webview打开h5链接下载问题

不是啊，并非只能下载鸿蒙相关的包。WebView需要应用侧主动设置下载委托（WebDownloadDelegate）来拦截并处理下载请求，才能实现任意文件（如APK、文档、图片等）的下载。

你先为WebView设置WebDownloadDelegate，并在其回调中启动下载、指定保存路径。

先确保权限已经加了

"permissions": [
  "ohos.permission.INTERNET",
  "ohos.permission.READ_USER_STORAGE",
  "ohos.permission.WRITE_USER_STORAGE"
]

在给 WebView 绑定 DownloadDelegate

import web_webview from '@ohos.web.webview';
import business_error, { BusinessError } from '@ohos.base';
import { picker } from '@kit.CoreFileKit';
import fs from '@ohos.file.fs';
import { fileUri } from '@kit.CoreFileKit';

@Entry
@Component
struct WebDownloadFilePage {
  controller: web_webview.WebviewController = new web_webview.WebviewController();
  delegate: web_webview.WebDownloadDelegate = new web_webview.WebDownloadDelegate();

  build() {
    Column() {
      Button('setDownloadDelegate')
        .onClick(() => {
          try {
            this.delegate.onBeforeDownload((webDownloadItem: web_webview.WebDownloadItem) => {
              console.log("======will start a download." + webDownloadItem.getSuggestedFileName());
              webDownloadItem.start("/data/storage/el2/base/cache/web/" + webDownloadItem.getSuggestedFileName());
            })
            this.delegate.onDownloadUpdated((webDownloadItem: web_webview.WebDownloadItem) => {
              console.log("======download update guid: " + webDownloadItem.getGuid());
            })
            this.delegate.onDownloadFailed((webDownloadItem: web_webview.WebDownloadItem) => {
              console.log("download failed guid: " + webDownloadItem.getGuid());
            })
            this.delegate.onDownloadFinish((webDownloadItem: web_webview.WebDownloadItem) => {
              console.log("======download finish guid: " + webDownloadItem.getGuid());
              console.log("======downloadFullPath:" + webDownloadItem.getFullPath())
              let documentSaveOptions = new picker.DocumentSaveOptions();
              documentSaveOptions.newFileNames = [webDownloadItem.getSuggestedFileName()];
              let documentPicker = new picker.DocumentViewPicker();
              documentSaveOptions.pickerMode = picker.DocumentPickerMode.DOWNLOAD;
              documentPicker.save(documentSaveOptions).then((documentSaveResult: Array<string>) => {
                let uri = documentSaveResult$1;
                let path: string = new fileUri.FileUri(uri).path
                let sanPath = "/data/storage/el2/base/cache/web/" + webDownloadItem.getSuggestedFileName()
                let sanFile = fs.openSync(sanPath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE)
                let pubFile = fs.openSync(path + '/***.pdf', fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE)
                fs.copyFileSync(sanFile.fd, pubFile.fd)
                console.info('DocumentViewPicker.save successfully, DocumentSaveResult uri: ' + JSON.stringify(documentSaveResult));
              }).catch((err: BusinessError) => {
                console.error('DocumentViewPicker.save failed with err: ' + JSON.stringify(err));
              });
            })
            this.controller.setDownloadDelegate(this.delegate);
          } catch (error) {
            let e: business_error.BusinessError = error as business_error.BusinessError;
            console.error(`ErrorCode: ${e.code}, Message: ${e.message}`);
          }
        })
      Button('startDownload')
        .onClick(() => {
          try {
            this.controller.startDownload('https://***.pdf');
          } catch (error) {
            let e: business_error.BusinessError = error as business_error.BusinessError;
            console.error(`ErrorCode: ${e.code}, Message: ${e.message}`);
          }
        })
      Web({ src: 'www.huawei.com', controller: this.controller })
        .fileAccess(true)
        .javaScriptAccess(true)
        .domStorageAccess(true)
    }.margin({ top: 200 })
  }
}