HarmonyOS 鸿蒙Next downloadFile 下载路径问题

HarmonyOS 鸿蒙Next downloadFile 下载路径问题 request.downloadFile下载的路径，可以直接传 DocumentViewPicker.picker拿到的路径吗？

2 回复

request.downloadFile 没法直接用拿到的路径，权限不够，可以先下载到沙箱，然后再用沙箱保存到公共目录

import { fileIo, fileUri, picker } from '@kit.CoreFileKit';
import { BusinessError, request } from '@kit.BasicServicesKit';
import { common } from '@kit.AbilityKit';

let context = getContext() as common.UIAbilityContext;
let filePath: string = context.filesDir + '/test.jpeg';
@Entry
@Component
struct DownLoadPage {
  @State message: string = 'Hello World';

  build() {
    Column() {
      Button('下载').onClick(() => {
        let documentOptions = new picker.DocumentSaveOptions()
        documentOptions.pickerMode = picker.DocumentPickerMode.DOWNLOAD
        let documentPicker = new picker.DocumentViewPicker()
        documentPicker.save(documentOptions,(err: BusinessError,DocumentSaveResult:Array<string>) => {
          request.downloadFile(context, {
            url: 'https://image.baidu.com/search/down?tn=download&word=download&ie=utf8&fr=detail&url=http%3A%2F%2Fpic1.win4000.com%2Fwallpaper%2F2019-11-22%2F5dd7afa7df0fc.jpg&thumburl=https%3A%2F%2Fimg1.baidu.com%2Fit%2Fu%3D2205810988%2C4283060315%26fm%3D253%26fmt%3Dauto%26app%3D138%26f%3DJPEG%3Fw%3D800%26h%3D500',
            filePath: filePath
          }, (err: BusinessError, data: request.DownloadTask) => {
            if (err) {
              console.error(`Failed to request the download. Code: ${err.code}, message: ${err.message}`);
              return;
            }
            let downloadTask: request.DownloadTask = data;
            downloadTask.on('complete', () => {
              console.log('complete')
              let file = fileIo.openSync(filePath, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE);
              let path: string = new fileUri.FileUri(DocumentSaveResult[0]).path
              let file2 = fileIo.openSync(path + '/' + file.name, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE)
              fileIo.copyFileSync(file.fd, file2.fd)
              fileIo.closeSync(file2);
              fileIo.closeSync(file);
              console.log('保存成功')
            });
            downloadTask.on('fail', (err: number) => {
              console.error(`Failed to download the task. Code: ${err}`);
            });
          });
        })
      })
    }
    .height('100%')
    .width('100%')
  }
}

更多关于HarmonyOS 鸿蒙Next downloadFile 下载路径问题的实战系列教程也可以访问 https://www.itying.com/category-93-b0.html


在HarmonyOS（鸿蒙Next）中，downloadFile API用于下载文件到指定路径。路径问题主要涉及如何指定文件保存的位置。鸿蒙系统提供了应用沙箱机制，文件存储分为内部存储和外部存储。内部存储路径通常为/data/data/包名/，外部存储路径为/storage/emulated/0/。

使用downloadFile时，可以通过filePath参数指定文件保存路径。若不指定路径，默认保存到应用的缓存目录。例如：

downloadFile({
  url: 'https://example.com/file.zip',
  filePath: '/data/data/com.example.app/files/file.zip',
  success: function(res) {
    console.log('文件下载成功');
  },
  fail: function(err) {
    console.log('文件下载失败');
  }
});

需要注意权限问题，访问外部存储需要申请ohos.permission.WRITE_USER_STORAGE权限。路径问题还涉及文件系统的访问控制，确保路径在应用沙箱范围内，避免越权访问。

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