对话框与通知
使用原生对话框进行文件选择、显示消息框和系统通知，提供一致且不打扰用户的体验
对话框与通知 是 CoddyKit 上的免费 Electron Desktop App Development 课时。 这是第 2 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Electron Desktop App Development 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Electron Desktop App Development 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Bridging Web and Desktop
Welcome to Lesson 2! In this lesson, we'll learn how to make your Electron app feel truly native by interacting with the operating system.
Desktop applications often need to ask users to select files, confirm actions, or provide timely updates. Electron provides dedicated modules for these tasks: Dialogs and Notifications.
Electron's `dialog` Module
The dialog module allows your Electron app to display native system dialogs for opening and saving files, or showing alert messages.
- Native Feel: These dialogs match the look and feel of the user's operating system (Windows, macOS, Linux).
- Blocking Interaction: Dialogs typically block the application's UI until the user interacts with them.
- Main Process Only: For security and consistency, the
dialogmodule can only be used from the main process.
Selecting Files with `showOpenDialog`
The dialog.showOpenDialog() method lets users select files or directories from their system. It returns a Promise that resolves with the selected paths or indicates if the dialog was canceled.
Key options include:
properties: An array like['openFile', 'multiSelections']to control selection type.filters: An array of objects like{ name: 'Images', extensions: ['jpg', 'png'] }to limit file types.
Code Demo: Open File Dialog
Try running this example. It will launch a simple Electron window and immediately display a native 'Open File' dialog. Select a file and check the console output!
const { app, BrowserWindow, dialog } = require('electron');
const path = require('path');
function createWindow() {
const mainWindow = new BrowserWindow({
width: 600,
height: 400,
webPreferences: {
preload: path.join(__dirname, 'preload.js'),
contextIsolation: true
}
});
mainWindow.loadURL('about:blank'); // Load a blank page
mainWindow.webContents.on('did-finish-load', async () => {
const result = await dialog.showOpenDialog(mainWindow, {
title: 'Select a File',
properties: ['openFile'],
filters: [
{ name: 'Text Files', extensions: ['txt'] },
{ name: 'All Files', extensions: ['*'] }
]
});
if (!result.canceled) {
console.log('Selected file:', result.filePaths[0]);
} else {
console.log('File selection canceled.');
}
});
}
app.whenReady().then(() => {
createWindow();
app.on('activate', () => {
if (BrowserWindow.getAllWindows().length === 0) {
createWindow();
}
});
});
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') {
app.quit();
}
});Saving User Data with `showSaveDialog`
When your app needs to save user-generated content, dialog.showSaveDialog() is your go-to. It prompts the user for a location and filename to save a file.
Useful options include:
defaultPath: A suggested path or filename (e.g.,app.getPath('documents') + '/untitled.txt').filters: Similar toshowOpenDialog, to suggest file types.
The dialog returns the chosen file path, or undefined if canceled.
const { app, BrowserWindow, dialog } = require('electron');
const path = require('path');
function createWindow() {
const mainWindow = new BrowserWindow({ width: 600, height: 400 });
mainWindow.loadURL('about:blank');
mainWindow.webContents.on('did-finish-load', async () => {
const result = await dialog.showSaveDialog(mainWindow, {
title: 'Save Your File',
defaultPath: app.getPath('documents') + '/my_document.txt',
filters: [
{ name: 'Text Files', extensions: ['txt'] },
{ name: 'All Files', extensions: ['*'] }
]
});
if (!result.canceled) {
console.log('File will be saved to:', result.filePath);
// In a real app, you'd write content to result.filePath here
} else {
console.log('Save operation canceled.');
}
});
}
app.whenReady().then(createWindow);
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit();
});Alerting Users with `showMessageBox`
For general alerts, confirmations, or error messages, use dialog.showMessageBox(). This displays a native message box with customizable buttons and text.
Key options:
type: 'none', 'info', 'warning', 'error', 'question'.buttons: An array of button labels (e.g.,['Save', 'Discard', 'Cancel']).message: The main message text.detail: Additional, more detailed information.
It returns the index of the button clicked by the user.
const { app, BrowserWindow, dialog } = require('electron');
const path = require('path');
function createWindow() {
const mainWindow = new BrowserWindow({ width: 600, height: 400 });
mainWindow.loadURL('about:blank');
mainWindow.webContents.on('did-finish-load', async () => {
const result = await dialog.showMessageBox(mainWindow, {
type: 'question',
title: 'Exit Application',
message: 'Do you want to save your changes?',
detail: 'Unsaved changes will be lost if you proceed without saving.',
buttons: ['Save', 'Discard', 'Cancel'],
defaultId: 0,
cancelId: 2
});
if (result.response === 0) {
console.log('User chose to Save.');
} else if (result.response === 1) {
console.log('User chose to Discard.');
} else {
console.log('User chose to Cancel.');
}
});
}
app.whenReady().then(createWindow);
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit();
});System Notifications with `Notification`
While dialogs demand immediate attention, the Notification module provides a non-intrusive way to inform users about events. These appear in the operating system's notification center.
- Non-Blocking: Notifications don't interrupt the user's workflow.
- Timely Info: Ideal for background task completion, new messages, or status updates.
- Main or Renderer: Can be used from both processes.
Sending a Simple Notification
Sending a notification is straightforward. You create a new Notification instance and call its show() method.
Common options include:
title: The main title of the notification.body: The detailed text content.icon: An optional path to an image icon.
It's good practice to check Notification.isSupported() before attempting to show a notification.
const { app, BrowserWindow, Notification } = require('electron');
const path = require('path');
function createWindow() {
const mainWindow = new BrowserWindow({ width: 600, height: 400 });
mainWindow.loadURL('about:blank');
mainWindow.webContents.on('did-finish-load', () => {
if (Notification.isSupported()) {
new Notification({
title: 'Electron App Update',
body: 'A new version is available! Click to install.',
// icon: path.join(__dirname, 'icon.png') // Optional
}).show();
console.log('Notification sent!');
} else {
console.log('Notifications are not supported on this system.');
}
});
}
app.whenReady().then(createWindow);
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit();
});Interactive Notifications
Notifications can be more than just static messages. You can add interactivity by listening for events like click or close. This allows users to take action directly from the notification itself.
For example, clicking a 'New Message' notification could bring the app window to the foreground or open a specific chat.
const { app, BrowserWindow, Notification } = require('electron');
const path = require('path');
function createWindow() {
const mainWindow = new BrowserWindow({ width: 600, height: 400 });
mainWindow.loadURL('about:blank');
mainWindow.webContents.on('did-finish-load', () => {
if (Notification.isSupported()) {
const myNotification = new Notification({
title: 'New Message!',
body: 'You have 3 unread messages.',
silent: false // Play a sound
});
myNotification.on('click', () => {
console.log('Notification clicked! Opening messages...');
mainWindow.show(); // Bring the window to front
});
myNotification.show();
console.log('Interactive notification sent.');
} else {
console.log('Notifications not supported.');
}
});
}
app.whenReady().then(createWindow);
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit();
});Dialogs vs. Notifications: When to Use Which?
Choosing between a dialog and a notification depends on the urgency and required user interaction:
- Dialogs: Use for critical information, user input (file selection, save location), or actions that block the app until resolved. They demand immediate attention.
- Notifications: Use for non-critical, time-sensitive information that doesn't require immediate action. They inform without interrupting the user's flow.
Always aim for a seamless and intuitive user experience by selecting the appropriate interaction method.
Quick Check: Dialogs or Notifications?
Which of the following scenarios are best suited for using Electron's dialog module? Select all that apply.
Recap & Next Steps
Great job! You've learned how to interact with the native operating system using Electron's dialog and Notification modules.
dialog: For critical, blocking interactions like file selection, saving, and message boxes. Only in the main process.Notification: For non-blocking, informative alerts that appear in the system notification center. Can be used in both processes.
Mastering these features helps your Electron app feel truly integrated into the user's desktop environment. Next up, we'll explore how to open external links and files using the shell module!
常见问题解答
「对话框与通知」课时是免费的吗？
是的 — 「对话框与通知」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Electron Desktop App Development 课程的其余内容，请升级到 CoddyKit PRO。 Electron Desktop App Development 课程共包含 4 节课。
「对话框与通知」这节课中我会学到什么？
使用原生对话框进行文件选择、显示消息框和系统通知，提供一致且不打扰用户的体验 你通过在浏览器中直接运行的动手代码来练习 Electron Desktop App Development，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Electron Desktop App Development 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Electron Desktop App Development 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 2 节课，共 4 节。
「对话框与通知」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Electron Desktop App Development 课中编写并运行代码吗？
能。每节 Electron Desktop App Development 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。