原生文件拖 & 放
- 概览
- 示例

原生文件拖 & 放

概览

作为桌面程序，当然希望能够实现操作系统的 drag & drop 功能。很多网站已经支持拖拽文件， Electron 当然也支持

要在您的应用中实现此功能，您需要调用 webContent.startDrag(item) API 响应 ondragstart 事件。

示例

一个演示如何动态创建要从窗口中拖出的文件的示例。

Preload.js

在 preload.js 中使用 contextBridge 注入方法 window.electron.startDrag(...) 将向主进程发送IPC消息。

const { contextBridge, ipcRenderer } = require('electron')
const path = require('node:path')
contextBridge.exposeInMainWorld('electron', {
  startDrag: (fileName) => {
    ipcRenderer.send('ondragstart', path.join(process.cwd(), fileName))
  }
})

Index.html

添加一个可拖动元素到 index.html, 并引用你的渲染器脚本：

<div style="border:2px solid black;border-radius:3px;padding:5px;display:inline-block" draggable="true" id="drag">拖动我</div>
<script src="renderer.js"></script>

Renderer.js

在 renderer.js 通过调用通过上述 contextBridge 添加的方法来设置渲染器进程处理拖动事件。

document.getElementById('drag').ondragstart = (event) => {
  event.preventDefault()
  window.electron.startDrag('drag-and-drop.md')
}

Main.js

在主进程中(main.js 文件)，将收到的事件带上文件路径和图标扩展到正在拖动的文件：

docs/fiddles/features/drag-and-drop (27.0.1)Open in Fiddle

main.js
preload.js
index.html
renderer.js

const { app, BrowserWindow, ipcMain } = require('electron')
const path = require('node:path')
const fs = require('node:fs')
const https = require('node:https')
function createWindow () {
  const win = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js')
    }
  })
  win.loadFile('index.html')
}
const iconName = path.join(__dirname, 'iconForDragAndDrop.png')
const icon = fs.createWriteStream(iconName)
// Create a new file to copy - you can also copy existing files.
fs.writeFileSync(path.join(__dirname, 'drag-and-drop-1.md'), '# First file to test drag and drop')
fs.writeFileSync(path.join(__dirname, 'drag-and-drop-2.md'), '# Second file to test drag and drop')
https.get('https://img.icons8.com/ios/452/drag-and-drop.png', (response) => {
  response.pipe(icon)
})
app.whenReady().then(createWindow)
ipcMain.on('ondragstart', (event, filePath) => {
  event.sender.startDrag({
    file: path.join(__dirname, filePath),
    icon: iconName
  })
})
app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})
app.on('activate', () => {
  if (BrowserWindow.getAllWindows().length === 0) {
    createWindow()
  }
})

const { contextBridge, ipcRenderer } = require('electron')
contextBridge.exposeInMainWorld('electron', {
  startDrag: (fileName) => {
    ipcRenderer.send('ondragstart', fileName)
  }
})

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Hello World!</title>
    <meta http-equiv="Content-Security-Policy" content="script-src 'self' 'unsafe-inline';" />
</head>
<body>
    <h1>Hello World!</h1>
    <p>Drag the boxes below to somewhere in your OS (Finder/Explorer, Desktop, etc.) to copy an example markdown file.</p>
    <div style="border:2px solid black;border-radius:3px;padding:5px;display:inline-block" draggable="true" id="drag1">Drag me - File 1</div>
    <div style="border:2px solid black;border-radius:3px;padding:5px;display:inline-block" draggable="true" id="drag2">Drag me - File 2</div>
    <script src="renderer.js"></script>
</body>
</html>

document.getElementById('drag1').ondragstart = (event) => {
  event.preventDefault()
  window.electron.startDrag('drag-and-drop-1.md')
}
document.getElementById('drag2').ondragstart = (event) => {
  event.preventDefault()
  window.electron.startDrag('drag-and-drop-2.md')
}

启动 Electron 应用程序后，尝试将该项从 BrowserWindow 拖放到桌面上。在本指南中，本项是位于项目根目录下的 Markdown 文件：