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标题: OpenHarmony应用如何上传下载文件 [打印本页]

作者: 深开鸿_石悌君 时间: 2023-12-18 11:02
标题: OpenHarmony应用如何上传下载文件
[md]### 简介：

使用[@ohos.request](https://gitee.com/openharmony/do ... /js-apis-request.md)接口创建上传和下载任务，实现上传、下载功能

### 文档环境：

* 开发环境：Windows 10家庭版
* DevEco Studio版本：DevEco Studio 4.0Release (4.0.0.600)
* SDK版本：4.0.10.13 (full sdk)
* API版本：Version 10
* 开发板型号：DAYU200(RK3568)
* 系统版本：OpenHarmony 4.1.2.2

### 演示demo：

* 设置request.agent.Config类型的上传/下载任务的配置信息：action和url是必选配置，action值为request.agent.Action.UPLOAD和request.agent.Action.DOWNLOAD，url值为资源地址
* 通过 let context = getContext(this) as common.UIAbilityContext并使用request.agent.create(context, config)创建上传或下载任务
* 通过on(‘progress’)订阅任务进度的事件，可以得到已上传/下载的字节数，app自定义算法显示上传下载进度比例显示在用户界面
* 通过on(‘completed’)订阅任务完成事件，on(‘failed’)订阅任务失败事件
* 上述准备工作完成后，调用Task的start函数开始文件上传下载
* 上传/下载演示界面如图

| 上传 | 下载|
| --- | --- |
|![upload.jpg](https://forums-obs.openharmony.c ... ify2m8129mb1cjp.jpg "upload.jpg")|![download.jpg](https://forums-obs.openharmony.c ... q4dtzdd0nh4q04v.jpg "download.jpg")|

* 上传文件核心代码如下

```
import common from '@ohos.app.ability.common';
import request from '@ohos.request';
import promptAction from '@ohos.promptAction';

class Upload {
  async uploadFile(fileUris: Array<string>, begin: number, end: number, callback: (progress: number, isSucceed: boolean) => void): Promise<void> {
// 查询到存在正在执行的上传任务，提示并返回
let tasks = await request.agent.search({
   state: request.agent.State.RUNNING,
   action: request.agent.Action.UPLOAD,
   mode: request.agent.Mode.FOREGROUND
});
if (tasks.length > 0) {
   promptAction.showToast({ message: $r('app.string.have_upload_task_tips'), bottom: TOAST_BOTTOM });
   return;
}
let context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext;
let config: request.agent.Config = {
   action: request.agent.Action.UPLOAD,
   headers: HEADER,
   url: await urlUtils.getUrl(context),
   mode: request.agent.Mode.FOREGROUND,
   method: 'POST',
   title: 'upload',
   network: request.agent.Network.ANY,
   data: await this.getFilesAndData(context.cacheDir, fileUris),
   token: UPLOAD_TOKEN,
   index: 0, // 指定片段上传的文件
   begins: begin,
   ends: end
};

try {
   this.uploadTask = await request.agent.create(context, config);
   this.uploadTask.on('progress', (progress: request.agent.Progress) => {
      let processed = Number(progress.processed.toString()).valueOf();
      let size = progress.sizes[progress.index];
      if (progress.index === 0) {
      if (end === -1) {
         size -= begin;
      } else {
         size = end - begin + 1;
      }
      }

      let process: number = Math.floor(processed / size * 100);
      if (process < 100) {
      callback(process, false);
      }
   });
   this.uploadTask.on('completed', (progress: request.agent.Progress) => {
      callback(100, true);
      this.cancelTask();
   });
   this.uploadTask.on('failed', async (progress: request.agent.Progress) => {
      if (this.uploadTask) {
      let taskInfo = await request.agent.touch(this.uploadTask.tid, UPLOAD_TOKEN);
      }
      callback(100, false);
      this.cancelTask();
   })
   await this.uploadTask.start();
} catch (err) {
   callback(100, false);
}
  }
}
```

* 下载文件核心代码如下

```
import common from '@ohos.app.ability.common';
import request from '@ohos.request';
import promptAction from '@ohos.promptAction';

class RequestDownload {
  async downloadFile(folder: string, url: string, callback: (progress: number, isSuccess: boolean) => void) {
// 查询到存在正在执行的下载任务，提示并返回
let tasks = await request.agent.search({
   state: request.agent.State.RUNNING,
   action: request.agent.Action.DOWNLOAD,
   mode: request.agent.Mode.FOREGROUND
});
if (tasks.length > 0) {
   promptAction.showToast({ message: $r('app.string.have_download_task_tips'), bottom: TOAST_BOTTOM });
   return;
}
let splitUrl = url.split('//')[1].split('/');
let context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext;
let downloadConfig: request.agent.Config = {
   action: request.agent.Action.DOWNLOAD,
   url: url,
   method: 'POST',
   title: 'download',
   mode: request.agent.Mode.FOREGROUND,
   network: request.agent.Network.ANY,
   saveas: `./${folder}/${splitUrl[splitUrl.length-1]}`,
   overwrite: true
}

try {
   this.downloadTask = await request.agent.create(context, downloadConfig);
   this.downloadTask.on('progress', (progress: request.agent.Progress) => {
      let processed = Number(progress.processed.toString()).valueOf();
      let size = progress.sizes[0];
      let process: number = Math.floor(processed / size * 100);
      if (process < 100) {
      callback(process, false);
      }
   })
   this.downloadTask.on('completed', (progress: request.agent.Progress) => {
      callback(100, true);
      this.deleteTask();
   })
   this.downloadTask.on('failed', async (progress: request.agent.Progress) => {
      if (this.downloadTask) {
      let taskInfo = await request.agent.show(this.downloadTask.tid);
      }
      callback(100, false);
      this.deleteTask();
   })
   await this.downloadTask.start();
} catch (err) {
   callback(100, false);
}
  }
}
```

### sample仓地址：

本功能的sample仓地址：[https://gitee.com/openharmony/applications\_app\_samples/tree/master/code/BasicFeature/Connectivity/UploadAndDownLoad](https://gitee.com/openharmony/ap ... y/UploadAndDownLoad)

[/md]

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