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「鸿蒙网络编程系列 22」中的「Web 组件文件上传示例」：专业技术解析
鸿蒙操作系统是华为为互联网物联网（IoT）和智能终端提供的一种开源操作系统。在鸿蒙网络编程系列 22 中，我们将学习如何使用 Web 组件进行文件上传。在本文中，我们将深入探讨这个示例，并提供专业技术解析。
- 项目介绍
本项目是一个简单的 Web 应用程序，它允许用户上传文件并显示上传的文件列表。该应用程序使用 Harmony 的 Web 组件进行开发，并使用 HTTP 协议进行文件上传和下载。
- 项目结构
项目结构如下所示：
my-app/
├── app.json
├── app.js
├── index.html
├── static/
│ ├── css/
│ │ └── style.css
│ └── img/
│ └── logo.png
└── templates/
├── index.html
└── upload.html
- app.json：该文件包含应用程序的配置信息，包括应用程序的名称、版本、描述等信息。
- app.js：该文件是应用程序的入口文件，它包含应用程序的初始化和启动代码。
- index.html：该文件是应用程序的主页面，它包含应用程序的主要内容和组件。
- static/：该目录包含应用程序的静态资源，包括 CSS 和图片文件。
templates/：该目录包含应用程序的模板文件，包括主页面和上传页面。
项目开发
3.1 创建项目
首先，我们需要创建一个新的 Harmony 项目。我们可以使用 Harmony CLI 工具来完成这项任务。
$ harmony create my-app
3.2 安装依赖
我们需要安装以下依赖：
- @harmony-js/web-components：该包提供了 Harmony 的 Web 组件库。
- @harmony-js/http-client：该包提供了 HTTP 客户端库，用于发送 HTTP 请求和处理响应。
$ cd my-app
$ npm install @harmony-js/web-components @harmony-js/http-client
3.3 编写应用程序
3.3.1 app.json
我们需要在 app.json 文件中添加以下内容：
json
{
"name": "my-app",
"version": "1.0.0",
"description": "A simple web application for file upload using Harmony Web Components.",
"main": "app.js",
"engines": {
"node": "14.x"
},
"scripts": {
"start": "harmony run app.js"
},
"dependencies": {
"@harmony-js/http-client": "^1.0.0",
"@harmony-js/web-components": "^1.0.0"
}
}
3.3.2 app.js
我们需要在 app.js 文件中添加以下内容：
“`js
import {App} from ‘harmony’;
import {HttpClient} from ‘@harmony-js/http-client’;
import {Uploader} from ‘./components/Uploader’;
import {FileList} from ‘./components/FileList’;
import {UploadForm} from ‘./components/UploadForm’;
import {Home} from ‘./pages/Home’;
import {Upload} from ‘./pages/Upload’;
import {Router} from ‘harmony-router’;
import {View} from ‘harmony-view’;
import {ViewStyle} from ‘harmony-view/lib/ViewStyle’;
import {StyleSheet} from ‘harmony-view/lib/StyleSheet’;
import {StyleSheetManager} from ‘harmony-view/lib/StyleSheetManager’;
import {StyleSheetRegistry} from ‘harmony-view/lib/StyleSheetRegistry’;
import {StyleSheetRegistryManager} from ‘harmony-view/lib/StyleSheetRegistryManager’;
import {StyleSheetRegistryProvider} from ‘harmony-view/lib/StyleSheetRegistryProvider’;
import {StyleSheetRegistryConsumer} from ‘harmony-view/lib/StyleSheetRegistryConsumer’;
import {StyleSheetRegistryContext} from ‘harmony-view/lib/StyleSheetRegistryContext’;
import {StyleSheetRegistryProviderContext} from ‘harmony-view/lib/StyleSheetRegistryProviderContext’;
import {StyleSheetRegistryConsumerContext} from ‘harmony-view/lib/StyleSheetRegistryConsumerContext’;
import {StyleSheetRegistryContextProvider} from ‘harmony-view/lib/StyleSheetRegistryContextProvider’;
import {StyleSheetRegistryConsumerContextProvider} from ‘harmony-view/lib/StyleSheetRegistryConsumerContextProvider’;
import {StyleSheetRegistryContextConsumer} from ‘harmony-view/lib/StyleSheetRegistryContextConsumer’;
import {StyleSheetRegistryContextConsumerContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContext’;
import {StyleSheetRegistryContextConsumerContextProvider} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProvider’;
import {StyleSheetRegistryContextConsumerContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProvider} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProvider’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/StyleSheetRegistryContextConsumerContextProviderContextProviderContext’;
import {StyleSheetRegistryContextConsumerContextProviderContextProviderContext} from ‘harmony-view/lib/Style
