Electron使用指南|Electron使用指南 - [03] Main Process API Electron使用指南-[03]MainProcessA

Main Process API

Electron API （Electron API 有三种）
Main Process （主进进程）
Renderer Process（渲染进程）
Share Modules（共享模块）

App 事件
ready:

当 Electron 完成初始化时被触发。

两种使用方法

app.on('ready', createWindow) app.on('ready', () => { console.log('App is ready!') createWindow() })

检查应用是否登录：app.isReady()
如果应用没有Ready，app.isReady()的值为 false

console.log('应用是否登录：' + app.isReady())

此时应用应该已经Ready

setTimeout(() => { console.log('应用是否登录：' + app.isReady()) }, 2000)

before-quit

在应用程序开始关闭窗口之前触发。

app.on('before-quit', (e) => { console.log('App is quiting') e.preventDefault() })

browser-window-blur

在 browserWindow 失去焦点时发出

app.on('browser-window-blur', (e) => { console.log('App unfocused') })

browser-window-focus

在 browserWindow 获得焦点时发出

app.on('browser-window-focus', (e) => { console.log('App focused') })

方法
app.quit()

app.on('browser-window-blur', (e) => { setTimeout(() => { app.quit() }, 3000) })app.on('browser-window-blur', (e) => { setTimeout(app.quit, 3000) })

app.getPath(name)

app.on('ready', () => { console.log(app.getPath('desktop')) console.log(app.getPath('music')) console.log(app.getPath('temp')) console.log(app.getPath('userData'))createWindow() })

BrowserWindow

【Electron使用指南|Electron使用指南 - [03] Main Process API】electron.BrowserWindow: 创建和控制浏览器窗口

实例方法
win.loadURL(url[, options]): 和 loadFile 互斥

mainWindow.loadURL('https://www.baidu.com')

优雅的显示窗口

使用ready-to-show事件

let mainWindow = new BrowserWindow({ show: false }) mainWindow.once('ready-to-show', () => { mainWindow.show() })

设置 backgroundColor

let win = new BrowserWindow({ backgroundColor: '#2e2c29' })

父子窗口

窗口定义

secondaryWindow = new BrowserWindow({ width: 600, height: 600, webPreferences: { nodeIntegration: true } })secondaryWindow.loadFile('index.html')secondaryWindow.on('closed',() => { mainWindow = null })

窗口关系

secondaryWindow = new BrowserWindow({ parent: mainWindon, // 定义父窗口 modal: true // 锁定在主窗口 })

子窗口显示和隐藏

secondaryWindow = new BrowserWindow({ show: false })setTimeout(() => { secondaryWindow.show() setTimeout(() => { secondaryWindow.hide() }, 3000) }, 2000)

无边框窗口

Frameless Window

mainWindow = new BrowserWindow({ frame: false })

让页面可拖拽

no-drag 修复下面控件的bug

显示红绿灯

mainWindow = new BrowserWindow({ titleBarStyle: 'hidden' // or hiddenInset 距离红绿灯更近 })

属性与方法
minWidth && minHeight

mainWindow = new BrowserWindow({ minWidth: 300, minHeight: 300 })

更多详见：https://electronjs.org/docs/api/browser-window#new-browserwindowoptions
窗口焦点事件

secWindow = new BrowserWindow({ width: 400, height: 300, webPreferences: { nodeIntegration: true }, })mainWindow.on('focus', () => { console.log('mainWindow focused') })secWindow.on('focus', () => { console.log('secWindow focused') })app.on('browser-window-focus', () => { console.log('App focused') })

静态方法

getAllWindows()

let allWindows = BrowserWindow.getAllWindows() console.log(allWindows)

更多详见: https://electronjs.org/docs/api/browser-window#%E9%9D%99%E6%80%81%E6%96%B9%E6%B3%95
实例属性

console.log(secWindow.id)

更多详见：https://electronjs.org/docs/api/browser-window#%E5%AE%9E%E4%BE%8B%E5%B1%9E%E6%80%A7
实例方法

maximize()secWindow.on('closed', () => { mainWindow.maximize() })
更多详见：https://electronjs.org/docs/api/browser-window#%E5%AE%9E%E4%BE%8B%E6%96%B9%E6%B3%95

state

electron-window-state 保存窗口的状态 npm install electron-window-state

webContents

webContents 是 EventEmitter 的实例，负责渲染和控制网页, 是 BrowserWindow 对象的一个属性。
let wc = mainWindow.webContents console.log(wc)

方法 getAllWebContents(）

返回 WebContents[] - 所有 WebContents 实例的数组。包含所有Windows，webviews，opened devtools 和 devtools 扩展背景页的 web 内容const {app, BrowserWindow, webContents} = require('electron') console.log(webContents.getAllWebContents())

实例事件

did-finish-load
dom-ready

文章图片

new-window

Kitten

before-input-event

wc.on('before-input-event', (e, input) => { console.log(`${input.key} : ${input.type}`) })

login
did-navigate

mainWindow.loadURL('https://httpbin.org/basic-auth/user/passwd')wc.on('login', (e, request, authInfo, callback) => { console.log('Logging in:') callback('user', 'passwd') })wc.on('did-navigate', (e, url, statusCode, message) => { console.log(`Navigated to: ${url}, with response code: ${statusCode}`) console.log(message) })

media-started-playing
media-paused

context-menu : 右键上下文信息

wc.on('context-menu', (e, params) => { console.log(`Context menu opened on: ${params.mediaType} at x:${params.x}, y:${params.y}`) })wc.on('context-menu', (e, params) => { console.log(`User seleted text: ${params.selectionText}`) console.log(`Selection can be copied: ${params.editFlags.canCopy}`) })

实例方法

executeJavaScript()

wc.on('context-menu', (e, params) => { wc.executeJavaScript(`alert('${params.selectionText}')`) })

Session

管理浏览器会话、cookie、缓存、代理设置等。

起步

创建session对象

let session = mainWindow.webContents.session console.log(session) // {}

在chromium 创建localStorage，然后创建两个窗口，两个session共享

mainWindow = new BrowserWindow({ width: 1000, height: 800, webPreferences: { nodeIntegration: true } })secWindow = new BrowserWindow({ width: 500, height: 400, webPreferences: { nodeIntegration: true } })let session = mainWindow.webContents.session let session2 = mainWindow.webContents.session console.log(Object.is(session, session2)) // true// Load index.html into the new BrowserWindow mainWindow.loadFile('index.html') secWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION! mainWindow.webContents.openDevTools(); secWindow.webContents.openDevTools(); // Listen for window being closed mainWindow.on('closed',() => { mainWindow = null }) secWindow.on('closed',() => { secWindow = null })

defaultSession

const {app, BrowserWindow, session} = require('electron') let ses = mainWindow.webContents.session console.log(Object.is(session.defaultSession, ses)) // true

自定义session

let customSes = session.fromPartition('part1') console.log(Object.is(customSes, ses)) //false, 此时customSes 还是共享sessionsecWindow = new BrowserWindow({ width: 500, height: 400, webPreferences: { nodeIntegration: true, session: customSes // 定义session, 此时子窗口有自己的session } })// 在子窗口里创建localstorge: winName/secWindow // 关闭所有窗口，发现创建的localstorage又消失了，因为此时的session存储在内存里，重新启动应用又消失了。可以加前缀persist，使其变为永久存储：let customSes = session.fromPartition('persist:part1')// 或者：secWindow = new BrowserWindow({ width: 500, height: 400, webPreferences: { nodeIntegration: true, - session: customSes + partition: 'persist:part1' } })

实例方法

ses.clearStorageData() // 删除主窗口的的storage

查询和修改一个会话的cookies

// 查询所有 cookies session.defaultSession.cookies.get({}) .then((cookies) => { console.log(cookies) }).catch((error) => { console.log(error) }) // 查询所有与设置的 URL 相关的所有 cookies session.defaultSession.cookies.get({ url: 'http://www.github.com' }) .then((cookies) => { console.log(cookies) }).catch((error) => { console.log(error) }) // 设置一个 cookie，使用设置的名称； // 如果存在，则会覆盖原先 cookie. const cookie = { url: 'http://www.github.com', name: 'dummy_name', value: 'dummy' } session.defaultSession.cookies.set(cookie) .then(() => { // success }, (error) => { console.error(error) })

downloadItem

控制来自于远程资源的文件下载。

Download Image// main.js let ses = session.defaultSessionses.on('will-download', (e, downloadItem, webContents) => {let fileName = downloadItem.getFilename() let fileSize = downloadItem.getTotalBytes()// Save to desktop downloadItem.setSavePath(app.getPath('desktop') + `/${fileName}`)downloadItem.on('updated', (e, state) => {let received = downloadItem.getReceivedBytes()if (state === 'progressing' && received) { let progress = Math.round((received/fileSize)*100) webContents.executeJavaScript(`window.progress.value = https://www.it610.com/article/${progress}`) } }) })

dialog - 对话框

显示用于打开和保存文件、警报等的本机系统对话框

const {app, BrowserWindow, dialog} = require('electron')mainWindow.webContents.on('did-finish-load', () => { dialog.showOpenDialog({ buttonLabel: '选择', defaultPath: app.getPath('desktop'), properties: ['multiSelections', 'createDirectory', 'openFile', 'openDirectory'] }, filepaths => { console.log(filepaths) }) }) dialog.showSaveDialog({}, filename => { console.log(filename) }) const answers = ['Yes', 'No', 'Maybe']dialog.showMessageBox({ title: 'Message Box', message: 'Please select an option', detail: 'Message details.', buttons: answers }, response => { console.log(`User selected: ${answers[response]}`) })

快捷键+系统快捷键

快捷键：定义键盘快捷键。系统快捷键：在应用程序没有键盘焦点时，监听键盘事件。

快捷键可以包含多个功能键和一个键码的字符串，由符号+结合，用来定义你应用中的键盘快捷键
示例：

CommandOrControl+A
CommandOrControl+Shift+Z

快捷方式使用 register 方法在 globalShortcut 模块中注册。
globalShortcut 模块可以在操作系统中注册/注销全局快捷键, 以便可以为操作定制各种快捷键。
注意: 快捷方式是全局的; 即使应用程序没有键盘焦点, 它也仍然在持续监听键盘事件。在应用程序模块发出 ready 事件之前, 不应使用此模块。

const {app, BrowserWindow, globalShortcut} = require('electron')globalShortcut.register('G', () => { console.log('User pressed G') }) globalShortcut.register('CommandOrControl+Y', () => { console.log('User pressed G with a combination key') globalShortcut.unregister('CommandOrControl+G') })

Menu 1、index.html

Hello World! - 锐客网 Hello World!We are using Node.js , and Electron .

2、main.js

// Modules const {app, BrowserWindow, Menu, MenuItem} = require('electron')// Keep a global reference of the window object, if you don't, the window will // be closed automatically when the JavaScript object is garbage collected. let mainWindowlet mainMenu = Menu.buildFromTemplate( require('./mainMenu') )// Create a new BrowserWindow when `app` is ready function createWindow () {mainWindow = new BrowserWindow({ width: 1000, height: 800, webPreferences: { nodeIntegration: true } })// Load index.html into the new BrowserWindow mainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION! mainWindow.webContents.openDevTools(); Menu.setApplicationMenu(mainMenu)// Listen for window being closed mainWindow.on('closed',() => { mainWindow = null }) }// Electron `app` is ready app.on('ready', createWindow)// Quit when all windows are closed - (Not macOS - Darwin) app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit() })// When app icon is clicked and app is running, (macOS) recreate the BrowserWindow app.on('activate', () => { if (mainWindow === null) createWindow() })

3、mainMenu.js

module.exports = [ { label: 'Electron', submenu: [ { label: 'Item 1'}, { label: 'Item 2', submenu: [ { label: 'Sub Item 1'} ]}, { label: 'Item 3'}, ] }, { label: 'Edit', submenu: [ { role: 'undo'}, { role: 'redo'}, { role: 'copy'}, { role: 'paste'}, ] }, { label: 'Actions', submenu: [ { label: 'DevTools', role: 'toggleDevTools' }, { role: 'toggleFullScreen' }, { label: 'Greet', click: () => { console.log('Hello from Main Menu') }, accelerator: 'Shift+Alt+G' } ] } ]

Context Menus 1、index.html

Hello World! - 锐客网 Hello World!We are using Node.js , and Electron .

2、main.js

// Modules const {app, BrowserWindow, Menu} = require('electron')// Keep a global reference of the window object, if you don't, the window will // be closed automatically when the JavaScript object is garbage collected. let mainWindowlet contextMenu = Menu.buildFromTemplate([ { label: 'Item 1' }, { role: 'editMenu' } ])// Create a new BrowserWindow when `app` is ready function createWindow () {mainWindow = new BrowserWindow({ width: 1000, height: 800, webPreferences: { nodeIntegration: true } })// Load index.html into the new BrowserWindow mainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION! mainWindow.webContents.openDevTools(); mainWindow.webContents.on('context-menu', e => { contextMenu.popup() })// Listen for window being closed mainWindow.on('closed',() => { mainWindow = null }) }// Electron `app` is ready app.on('ready', createWindow)// Quit when all windows are closed - (Not macOS - Darwin) app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit() })// When app icon is clicked and app is running, (macOS) recreate the BrowserWindow app.on('activate', () => { if (mainWindow === null) createWindow() })

Tray (托盘) 1、main.js

// Modules const {app, BrowserWindow, Tray, Menu} = require('electron')// Keep a global reference of the window object, if you don't, the window will // be closed automatically when the JavaScript object is garbage collected. let mainWindow, traylet trayMenu = Menu.buildFromTemplate([ { label: 'Item 1' }, { role: 'quit' } ])function createTray() {tray = new Tray('trayTemplate@2x.png') tray.setToolTip('Tray details')tray.on('click', e => {if (e.shiftKey) { app.quit() } else { mainWindow.isVisible() ? mainWindow.hide() : mainWindow.show() } })tray.setContextMenu(trayMenu) }// Create a new BrowserWindow when `app` is ready function createWindow () {createTray()mainWindow = new BrowserWindow({ width: 1000, height: 800, webPreferences: { nodeIntegration: true } })// Load index.html into the new BrowserWindow mainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION! mainWindow.webContents.openDevTools(); // Listen for window being closed mainWindow.on('closed',() => { mainWindow = null }) }// Electron `app` is ready app.on('ready', createWindow)// Quit when all windows are closed - (Not macOS - Darwin) app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit() })// When app icon is clicked and app is running, (macOS) recreate the BrowserWindow app.on('activate', () => { if (mainWindow === null) createWindow() })

powerMonitor (电源指示器)

// Modules const electron = require('electron') const {app, BrowserWindow} = electron// Keep a global reference of the window object, if you don't, the window will // be closed automatically when the JavaScript object is garbage collected. let mainWindow// Create a new BrowserWindow when `app` is ready function createWindow () {mainWindow = new BrowserWindow({ width: 1000, height: 800, webPreferences: { nodeIntegration: true } })// Load index.html into the new BrowserWindow mainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION! mainWindow.webContents.openDevTools(); // Listen for window being closed mainWindow.on('closed',() => { mainWindow = null })electron.powerMonitor.on('resume', e => { if(!mainWindow) createWindow() })electron.powerMonitor.on('suspend', e => { console.log('Saving some data') }) }// Electron `app` is ready app.on('ready', createWindow)// Quit when all windows are closed - (Not macOS - Darwin) app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit() })// When app icon is clicked and app is running, (macOS) recreate the BrowserWindow app.on('activate', () => { if (mainWindow === null) createWindow() })