web前端培训分享Electron之Main Process API
本節由千鋒web前端培訓機構講師給大家分享Electron使用指南之Main Process API，Electron API （Electron API 有三種） Main Process （主進進程） Renderer Process（渲染進程） Share Modules（共享模塊）
App
事件
ready:
當 Electron 完成初始化時被觸發。
兩種使用方法
app.on(‘ready’, createWindow)
app.on(‘ready’, () => {
console.log(‘App is ready!’)
createWindow()
})
檢查應用是否登錄：app.isReady()
如果應用沒有Ready，app.isReady()的值為 false
console.log(‘應用是否登錄：’ + app.isReady())
此時應用應該已經Ready
setTimeout(() => {
console.log(‘應用是否登錄：’ + app.isReady())
}, 2000)
before-quit
在應用程序開始關閉窗口之前觸發。
app.on(‘before-quit’, (e) => {
console.log(‘App is quiting’)
e.preventDefault()
})
browser-window-blur
在 browserWindow 失去焦點時發出
app.on(‘browser-window-blur’, (e) => {
console.log(‘App unfocused’)
})
browser-window-focus
在 browserWindow 獲得焦點時發出
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.BrowserWindow: 創建和控制瀏覽器窗口
實例方法
win.loadURL(url[, options]): 和 loadFile 互斥
mainWindow.loadURL(‘https://www.baidu.com’)
優雅的顯示窗口
使用ready-to-show事件
let mainWindow = new BrowserWindow({ show: false })
mainWindow.once(‘ready-to-show’, () => {
mainWindow.show()
})
設置 backgroundColor
let win = new BrowserWindow({ backgroundColor: ‘#2e2c29’ })
父子窗口
窗口定義
secondaryWindow = new BrowserWindow({
width: 600,
height: 600,
webPreferences: { nodeIntegration: true }
})
secondaryWindow.loadFile(‘index.html’)
secondaryWindow.on(‘closed’, () => {
mainWindow = null
})
窗口關系
secondaryWindow = new BrowserWindow({
parent: mainWindon, // 定義父窗口
modal: true // 鎖定在主窗口
})
子窗口顯示和隱藏
secondaryWindow = new BrowserWindow({
show: false
})
setTimeout(() => {
secondaryWindow.show()
setTimeout(() => {
secondaryWindow.hide()
}, 3000)
}, 2000)
無邊框窗口
Frameless Window
mainWindow = new BrowserWindow({
frame: false
})
讓頁面可拖拽
< body style=“user-select: none; -webkit-app-region:drag;”>
no-drag 修復下面控件的bug
< input style="-webkit-app-region: no-drag;" type=“range” name=“range” min=“0” max=“10”>
顯示紅綠燈
mainWindow = new BrowserWindow({
titleBarStyle: ‘hidden’ // or hiddenInset 距離紅綠燈更近
})
屬性與方法
minWidth && minHeight
mainWindow = new BrowserWindow({
minWidth: 300,
minHeight: 300
})
窗口焦點事件
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’)
})
靜態方法
getAllWindows()
let allWindows = BrowserWindow.getAllWindows()
console.log(allWindows)
實例屬性
id
console.log(secWindow.id)
實例方法
maximize()secWindow.on(‘closed’, () => { mainWindow.maximize() })
state
electron-window-state 保存窗口的狀態 npm install electron-window-state
webContents
webContents 是 EventEmitter 的實例， 負責渲染和控制網頁, 是 BrowserWindow 對象的一個屬性。 let wc = mainWindow.webContents console.log(wc)
方法 getAllWebContents(）
返回 WebContents[] - 所有 WebContents 實例的數組。 包含所有Windows，webviews，opened devtools 和 devtools 擴展背景頁的 web 內容const {app, BrowserWindow, webContents} = require(‘electron’) console.log(webContents.getAllWebContents())
實例事件
did-finish-loaddom-ready<div><img src="https://placekitten.com/500/500" alt=""></div><script>let wc = mainWindow.webContentswc.on('did-finish-load', () => {console.log('Conent fully loaded')})wc.on('dom-ready', () => {console.log('DOM Ready')})</script>new-window<div><a target="_blank" href="https://placekitten.com/500/500"><h3>Kitten</h3></a></div><script>wc.on('new-window', (e, url) => {e.preventDefault()console.log('DOM Ready')})</script>before-input-eventwc.on('before-input-event', (e, input) => {console.log(`${input.key} : ${input.type}`)})logindid-navigatemainWindow.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-playingmedia-paused<div><video src="./mgm.mp4" controls width="400"></video></div><script>wc.on('media-started-playing', () => {console.log('Video Started')})wc.on('media-paused', () => {console.log('Video Paused')})</script>context-menu : 右鍵上下文信息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: ${params.editFlags.canCopy}`)})實例方法
executeJavaScript()
wc.on(‘context-menu’, (e, params) => {
wc.executeJavaScript(alert('${params.selectionText}'))
})
Session
管理瀏覽器會話、cookie、緩存、代理設置等。
起步
創建session對象
let session = mainWindow.webContents.session
console.log(session) // {}
在chromium 創建localStorage，然后創建兩個窗口，兩個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
自定義session
let customSes = session.fromPartition(‘part1’)
console.log(Object.is(customSes, ses)) //false, 此時customSes 還是共享session
secWindow = new BrowserWindow({
width: 500, height: 400,
webPreferences: {
nodeIntegration: true,
session: customSes // 定義session, 此時子窗口有自己的session
}
})
// 在子窗口里創建localstorge: winName/secWindow
// 關閉所有窗口，發現創建的localstorage又消失了，因為此時的session存儲在內存里，重新啟動應用又消失了?？梢约忧熬Ypersist，使其變為永久存儲：
let customSes = session.fromPartition('persist:part1')// 或者：secWindow = new BrowserWindow({width: 500, height: 400,webPreferences: {nodeIntegration: true,- session: customSes+ partition: 'persist:part1'}})實例方法
ses.clearStorageData() // 刪除主窗口的的storage
cookie
查詢和修改一個會話的cookies
// 查詢所有 cookiessession.defaultSession.cookies.get({}).then((cookies) => {console.log(cookies)}).catch((error) => {console.log(error)})// 查詢所有與設置的 URL 相關的所有 cookiessession.defaultSession.cookies.get({ url: 'http://www.github.com' }).then((cookies) => {console.log(cookies)}).catch((error) => {console.log(error)})// 設置一個 cookie，使用設置的名稱；// 如果存在，則會覆蓋原先 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
控制來自于遠程資源的文件下載。
<h2><a href="https://picsum.photos/5000/5000/" download>Download Image</a></h2><progress value="0" max="100" id="progress"></progress><script>window.progress = document.getElementById('progress')</script>// main.jslet ses = session.defaultSessionses.on('will-download', (e, downloadItem, webContents) => {let fileName = downloadItem.getFilename()let fileSize = downloadItem.getTotalBytes()// Save to desktopdownloadItem.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 - 對話框
顯示用于打開和保存文件、警報等的本機系統對話框
const {app, BrowserWindow, dialog} = require('electron')mainWindow.webContents.on('did-finish-load', () => {dialog.showOpenDialog({buttonLabel: '選擇',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]}`)})快捷鍵+系統快捷鍵
快捷鍵：定義鍵盤快捷鍵。 系統快捷鍵：在應用程序沒有鍵盤焦點時，監聽鍵盤事件。
快捷鍵可以包含多個功能鍵和一個鍵碼的字符串，由符號+結合，用來定義你應用中的鍵盤快捷鍵
示例：
CommandOrControl+A
CommandOrControl+Shift+Z
快捷方式使用 register 方法在 globalShortcut 模塊中注冊。
globalShortcut 模塊可以在操作系統中注冊/注銷全局快捷鍵, 以便可以為操作定制各種快捷鍵。
注意: 快捷方式是全局的; 即使應用程序沒有鍵盤焦點, 它也仍然在持續監聽鍵盤事件。 在應用程序模塊發出 ready 事件之前, 不應使用此模塊。
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 <strong><script>document.write( process.versions.node)</script></strong>,and Electron <strong><script>document.write( process.versions.electron )</script></strong>.<script>// You can also require other files to run in this processrequire('./renderer.js')</script></body></html>2、main.js
// Modulesconst {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 readyfunction createWindow () {mainWindow = new BrowserWindow({width: 1000, height: 800,webPreferences: { nodeIntegration: true }})// Load index.html into the new BrowserWindowmainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION!mainWindow.webContents.openDevTools();Menu.setApplicationMenu(mainMenu)// Listen for window being closedmainWindow.on('closed', () => {mainWindow = null})}// Electron `app` is readyapp.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 BrowserWindowapp.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 <strong><script>document.write( process.versions.node)</script></strong>,and Electron <strong><script>document.write( process.versions.electron )</script></strong>.<script>// You can also require other files to run in this processrequire('./renderer.js')</script></body></html>2、main.js
// Modulesconst {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 readyfunction createWindow () {mainWindow = new BrowserWindow({width: 1000, height: 800,webPreferences: { nodeIntegration: true }})// Load index.html into the new BrowserWindowmainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION!mainWindow.webContents.openDevTools();mainWindow.webContents.on('context-menu', e => {contextMenu.popup()})// Listen for window being closedmainWindow.on('closed', () => {mainWindow = null})}// Electron `app` is readyapp.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 BrowserWindowapp.on('activate', () => {if (mainWindow === null) createWindow()})Tray (托盤)
1、main.js
// Modulesconst {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 readyfunction createWindow () {createTray()mainWindow = new BrowserWindow({width: 1000, height: 800,webPreferences: { nodeIntegration: true }})// Load index.html into the new BrowserWindowmainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION!mainWindow.webContents.openDevTools();// Listen for window being closedmainWindow.on('closed', () => {mainWindow = null})}// Electron `app` is readyapp.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 BrowserWindowapp.on('activate', () => {if (mainWindow === null) createWindow()})powerMonitor (電源指示器)// Modulesconst 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 readyfunction createWindow () {mainWindow = new BrowserWindow({width: 1000, height: 800,webPreferences: { nodeIntegration: true }})// Load index.html into the new BrowserWindowmainWindow.loadFile('index.html')// Open DevTools - Remove for PRODUCTION!mainWindow.webContents.openDevTools();// Listen for window being closedmainWindow.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 readyapp.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 BrowserWindowapp.on('activate', () => {if (mainWindow === null) createWindow()})本文來自千鋒教育，轉載請注明出處。
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