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Electron 使用指南之 Main Process API，Electron API（Electron API 有三种）Main Process（主进过程）Renderer Process（渲染过程）Share Modules（共享模块）
App
事件
ready:
当 Electron 实现初始化时被触发。
两种应用办法
app.on(‘ready’, createWindow)
app.on(‘ready’, () => {
console.log(‘App is ready!’)
createWindow()
})
查看利用是否登录：app.isReady()
如果利用没有 Ready，app.isReady() 的值为 false
console.log(‘ 利用是否登录：’ + app.isReady())
此时利用应该曾经 Ready
setTimeout(() => {
console.log(‘ 利用是否登录：’ + app.isReady())
}, 2000)
before-quit
在应用程序开始敞开窗口之前触发。
app.on(‘before-quit’, (e) => {
console.log(‘App is quiting’)
e.preventDefault()
})
browser-window-blur
在 browserWindow 失去焦点时收回
app.on(‘browser-window-blur’, (e) => {
console.log(‘App unfocused’)
})
browser-window-focus
在 browserWindow 取得焦点时收回
app.on(‘browser-window-focus’, (e) => {
console.log(‘App focused’)
})
办法
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.BrowserWindow: 创立和管制浏览器窗口
实例办法
win.loadURL(url[, options]): 和 loadFile 互斥
mainWindow.loadURL(‘)
优雅的显示窗口
应用 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
})
子窗口显示和暗藏
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
<body style=”user-select: none; -webkit-app-region:drag;”>
no-drag 修复页游上面控件的 bug
<input style=”-webkit-app-region: no-drag;” type=”range” name=”range” min=”0″ max=”10″>
显示红绿灯
mainWindow = new BrowserWindow({
titleBarStyle: ‘hidden’ // or hiddenInset 间隔红绿灯更近
})
属性与办法
minWidth && minHeight
mainWindow = new BrowserWindow({
minWidth: 300,
minHeight: 300
})
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)
实例属性
id
console.log(secWindow.id)
实例办法
maximize()secWindow.on(‘closed’, () => {mainWindow.maximize() })
state
electron-window-state 保留窗口的状态 npm install electron-window-state
webContents
webContents 是 EventEmitter 的实例，负责渲染和管制网页, 是 BrowserWindow 对象的一个属性。let wc = mainWindow.webContents console.log(wc)
办法 getAllWebContents(）
返回 WebContents[] – 所有 WebContents 实例的数组。蕴含所有 Windows，webviews，opened devtools 和 devtools 扩大背景页的 web 内容 const {app, BrowserWindow, webContents} = require(‘electron’) console.log(webContents.getAllWebContents())
实例事件
did-finish-load
dom-ready
<div>
<img src=” alt=””>
</div>
<script>
let wc = mainWindow.webContents
wc.on(‘did-finish-load’, () => {
console.log(‘Conent fully loaded’)
})
wc.on(‘dom-ready’, () => {
console.log(‘DOM Ready’)
})
</script>
new-window
<div>
Download Image</h2>
<progress value=”0″ max=”100″ id=”progress”></progress>
<script>
window.progress = document.getElementById(‘progress’)
</script>
// main.js
let ses = session.defaultSession
ses.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 = ${progress})
}
})
})
dialog – 对话框
显示用于关上和保留文件、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: ‘ 抉择 ’,
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 + 零碎快捷键
快捷键：定义键盘快捷键。零碎快捷键：在应用程序没有键盘焦点时，监听键盘事件。
快捷键能够蕴含多个功能键和一个键码的字符串，由符号 + 联合，用来定义你利用中的键盘快捷键
示例：
CommandOrControl+A
CommandOrControl+Shift+Z
快捷方式应用 register 办法在 globalShortcut 模块中注册。
globalShortcut 模块能够在操作系统中注册 / 登记全局快捷键, 以便能够为操作定制各种快捷键。
留神: 快捷方式是全局的; 即便应用程序没有键盘焦点, 它也依然在继续监听键盘事件。在利用程序模块收回 ready 事件之前, 不应应用此模块。
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
<!DOCTYPE html>
<html>
<head>
<meta charset=”UTF-8″>
<meta http-equiv=”Content-Security-Policy” content=”script-src ‘self’ ‘unsafe-inline'”>
<title>Hello World!</title>
</head>
<body>
<h1>Hello World!</h1>
<textarea name=”name” rows=”8″ cols=”80″></textarea>
<!– All of the Node.js APIs are available in this renderer process. –>
We are using Node.js <script>document.write(process.versions.node)</script>,
and Electron <script>document.write(process.versions.electron)</script>.
<script>
// You can also require other files to run in this process
require(‘./renderer.js’)
</script>
</body>
</html>
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 mainWindow
let 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
<!DOCTYPE html>
<html>
<head>
<meta charset=”UTF-8″>
<meta http-equiv=”Content-Security-Policy” content=”script-src ‘self’ ‘unsafe-inline'”>
<title>Hello World!</title>
</head>
<body>
<h1>Hello World!</h1>
<textarea name=”name” rows=”8″ cols=”80″></textarea>
<!– All of the Node.js APIs are available in this renderer process. –>
We are using Node.js <script>document.write(process.versions.node)</script>,
and Electron <script>document.write(process.versions.electron)</script>.
<script>
// You can also require other files to run in this process
require(‘./renderer.js’)
</script>
</body>
</html>
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 mainWindow
let 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, tray
let 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()
})
