共享API (Shared API)
本节重点讲解 process、screen、shell、nativeImage、clipboard 几个部分内容。
1、process (进程)
1.1 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>
<!-- 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>.
<br><button type="button" onclick="process.hang()">Hang Renderer</button>
<br><button type="button" onclick="process.crash()">Crash Renderer</button>
<script>
// let i = 1
// setInterval(() => {
// console.log(i)
// i++
// }, 500)
</script>
</body>
</html>
1.2 main.js
// Modules
const {app, BrowserWindow} = 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
// 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( 'crashed', mainWindow.reload )
// 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()
})
2、screen (屏幕)
1.1 main.js
// 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 () {
let primaryDisplay = electron.screen.getPrimaryDisplay()
mainWindow = new BrowserWindow({
x: primaryDisplay.bounds.x, y: primaryDisplay.bounds.y,
width: primaryDisplay.size.width/2, height: primaryDisplay.size.height,
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()
})
1.2 renderer.js
const electron = require('electron')
const displays = electron.screen.getAllDisplays()
console.log( `${displays[0].size.width} x ${displays[0].size.height}` )
console.log( `${displays[0].bounds.x}, ${displays[0].bounds.y}` )
console.log( `${displays[1].size.width} x ${displays[1].size.height}` )
console.log( `${displays[1].bounds.x}, ${displays[1].bounds.y}` )
electron.screen.on( 'display-metrics-changed', (e, display, metricsChanged) => {
console.log( metricsChanged )
})
document.getElementsByTagName('body')[0].addEventListener( 'click', e => {
console.log( electron.screen.getCursorScreenPoint() )
})
3、shell
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="Content-Security-Policy" content="script-src 'self' 'unsafe-inline'">
<title>Hello World!</title>
</head>
<body>
<h1>Hello World!</h1>
<button onclick="showSite()">Launch Electron.js Site</button><br>
<button onclick="openSplash()">Open Splash.png</button><br>
<button onclick="showSplashFile()">Show Splash.png</button><br>
<button onclick="deleteSplashFile()">Delete Splash.png</button><br>
<script>
const { shell } = require('electron')
const showSite = e => {
shell.openExternal('https://electronjs.org')
}
const splashPath = `${__dirname}/splash.png`
const openSplash = e => {
shell.openItem(splashPath)
}
const showSplashFile = e => {
shell.showItemInFolder(splashPath)
}
const deleteSplashFile = e => {
shell.moveItemToTrash(splashPath)
}
</script>
</body>
</html>
4、nativeImage (本地图片)
<!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>Convert splash.png:</h1>
<button onclick="toPng()">PNG</button>
<button onclick="toJpg()">JPG</button>
<button onclick="toTag()">Show</button>
<br><img src="" id="preview">
<script>
const fs = require('fs')
const { nativeImage, remote } = require('electron')
const splash = nativeImage.createFromPath(`${__dirname}/splash.png`)
const saveToDesktop = (data, ext) => {
let desktopPath = remote.app.getPath('desktop')
fs.writeFile( `${desktopPath}/splash.${ext}`, data, console.log )
}
const toTag = e => {
let size = splash.getSize()
let splashURL = splash.resize({ width: size.width/4, height: size.height/4 }).toDataURL()
document.getElementById('preview').src = splashURL
}
const toPng = e => {
let pngSplash = splash.toPNG()
saveToDesktop( pngSplash, 'png' )
}
const toJpg = e => {
let jpgSplash = splash.toJPEG(100)
saveToDesktop( jpgSplash, 'jpg' )
}
</script>
</body>
</html>
5、clipboard（剪贴板）
5.1 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>
<!-- 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>.
<br><button onclick="makeUpper()">Make clipboard uppercase</button>
<br><button onclick="showImage()">Show clipboard image</button>
<br><img src="" id="cbImage">
<script>
const { clipboard } = require('electron')
console.log( clipboard.readText() )
const showImage = e => {
let image = clipboard.readImage()
document.getElementById('cbImage').src = image.toDataURL()
}
const makeUpper = e => {
let cbText = clipboard.readText()
clipboard.writeText( cbText.toUpperCase() )
}
</script>
</body>
</html>
5.2 main.js
// Modules
const {app, BrowserWindow, clipboard} = 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
// Create a new BrowserWindow when `app` is ready
function createWindow () {
clipboard.writeText('Hello from the main process!')
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()
})
