The following modules are available to the main process in Electron:
| The module | describe |
|---|---|
| app | Responsible for controlling the entire life cycle of the application |
| autoUpdater | The module provides a toSquirrelAutomatically update the interface of the framework |
| BrowserWindow | Can be used to create a new browser window |
| contentTracing | Used to collectChromiumTrace information generated by the content module |
| dialog | Use to display native system dialogs, such as open file dialogs |
| global-Shortcut | Keyboard shortcuts for registering and logging out globally |
| ipcMain | The module isEventEmitterAn instance object used in the main process that can send synchronous or asynchronous messages to interact with the renderer |
| Menu | Use to create a native menu, such as a context menu |
| MenuItem | Add menu subitems to the back and forth menu |
| powerMonitor | Used to show battery power changes, can only be used in the main process, and only if the Ready event has been issued |
| powerSaveBlocker | It prevents the system from going into power-saving mode, sleep mode |
| protocol | Used to register a custom protocol or to declare the use of an existing protocol |
| session | To create a newSessionObject, save local objects and other operations |
| webContents | This is aEventEmitter, responsible for rendering and controlling a web page, is aBrowserWindowThe properties of the |
| Tray | aTrayOne representing an operating system notification areaicon, is usually bound to a context menu |
App module
APP modules are designed to control the entire application life cycle.
Example:
For example, exit the application when the last window is closed:
const app = require('app');
app.on('window-all-closed', function(){
app.quit();
});The App object can emit the following events:
| The event | describe |
|---|---|
| will-finish-launching | When the program completes the basic startup, similar toreadyThe event |
| ready | whenElectronTriggered when initialization is complete |
| window-all-closed | Triggered when all Windows have been closed. Triggered only when the program is about to be pushed to exit. If you call theapp.quit()It won’t fire |
| before-quit | Called when the program begins to close the windowevent.prevertDefault()The default behavior of the application is prevented |
| will-quit | This event is emitted when the program is about to exit and the window has already closed |
| quit | Triggered when the application is exiting |
AutoUpdater module
The autoupater module provides an interface to the Squirrel automatic update framework.
The AutoOutPdater object fires the following events:
| The event | describe |
|---|---|
| error | Triggered when an update occurs with an error |
| checking-for-update | Triggered when you start checking for updates |
| update-available | Triggered when an update is found available, the update pack download starts automatically |
| update-not-available | Triggered when no updates are available |
| update-downloaded | Triggered when the update download is complete |
BrowserWindow module
The BrowserWindow module is used to create a new BrowserWindow.
Example:
// In the main process const BrowserWindow = require('electron').BrowserWindow; // const BrowserWindow = require('electron').remote.BrowserWindow; var win = new BrowserWindow({ width: 800, height: 400, show: false }); win.on('closed', function() { win = null; }); win.loadURL('https://github.com'); win.show();The BrowserWindow object can fire the following events:
| The event | describe |
|---|---|
| close | It fires when the window is about to close, it’s inDOM 的 beforeunload 和 unloadEvent before firing, usedevent.preventDefault()You can cancel this operation |
| closed | When the window is closed, when you receive this event, you should delete the reference object to the closed window and avoid using it again |
| unresponsive | Trigger an event when the interface is stuck |
| responsive | Triggered when interface recovery is stuck |
| blur | Triggered when the window loses focus |
| focus | Triggered when the window gets focus |
| maximize | Triggered when the window is maximized |
| unmaximize | Triggered when the window exit is maximized |
| minimize | Triggered when the window is minimized |
| restore | Triggered when the window is restored from minimization |
| resize | In the windowsizeTriggered when you change |
| move | Triggered when the window movesOS XThe alias formoved |
ContentTracing module
The ContentTracing module is used to collect the search data generated by the underlying Chromium content module. This module does not have a web interface, so we need to add Chrome :// Tracing/to the Chrome browser to load the generated files and view the results.
Example:
const contentTracing = require('contentTracing').;
const options = {
categoryFilter: '*',
traceOptions: 'record-until-full,enable-sampling'
}
contentTracing.startRecording(options, function() {
console.log('Tracing started');
setTimeout(function() {
contentTracing.stopRecording('', function(path) {
console.log('Tracing data recorded to ' + path);
});
}, 3000);
});The methods of the Content-Tracing module are as follows:
| methods | describe |
|---|---|
| getCategories | Gets a set of taxonomy groups that can be changed to a new code path |
| startRecording | Start recording to all processes. Once a request is received to start recording, the recording is started immediately and is recorded asynchronously in the child processes |
| stopRecording | Stops recording of all child processes |
| startMonitoring | Start listening to all processes |
| stopMonitoring | Stop listening on all child processes |
| captureMonitoringSnapshot | Gets the lookup data for the current listening |
| getTraceBufferUsag | By looking forbufferProcess to get the percentage maximum usage |
| setWatchEvent | Called at any time on any process when a specified event occurscallback |
| cancelWatchEvent | cancelwatchEvent, which might be caused if a lookup is startedwatchError in callback function for event |
Dialog module
The Dialog module provides APIs to display native system dialogs, such as open file boxes or alert boxes. So web applications can give users the same experience as system applications.
Example:
A dialog box example that shows how to select files and directories:
var win = ... ; // Display the dialog const dialog = require('electron').dialog; console.log(dialog.showOpenDialog({ properties: [ 'openFile', 'openDirectory', 'multiSelections' ]}));Global – shortcut module
The global-shortcut module is used to set up shortcuts for various custom operations. Note that the shortcut keys registered with this module are global to the system and do not use this module before the application module responds to the Ready message.
Example:
var app = require('app'); var globalShortcut = require('electron').globalShortcut; App. on('ready', function() {var ret = globalShortcut. Register (' CTRL +x', 'CTRL +x'); function() { console.log('ctrl+x is pressed'); }) if (! ret) { console.log('registration failed'); } / / check whether registered the 'CTRL + x' shortcut. The console log (globalShortcut. IsRegistered (' CTRL + x)); }); App. On (' will - quit ', function () {/ / logout "CTRL + x" shortcut globalShortcut. Unregister (CTRL + x "); / / cancel all shortcuts globalShortcut. UnregisterAll (); });IpcMain module
The IPCMain module is an instance of the EventEmitter class that, when used in the main process, controls the asynchronous or synchronous messages sent from the renderer process that trigger events.
Example:
Here is an example of sending and processing messages between the main process and the renderer process.
Main process:
const ipcMain = require('electron').ipcMain; ipcMain.on('asynchronous-message', function(event, arg) { console.log(arg); // PingEvent.Sender.Send (' Asynchronous -reply', 'Pong '); }); ipcMain.on('synchronous-message', function(event, arg) { console.log(arg); // output ping event.returnValue = 'pong'; });Render process:
const ipcRenderer = require('electron').ipcRenderer; console.log(ipcRenderer.sendSync('synchronous-message', 'ping')); // Pong iPcrenderer. on(' Asynchronous - Reply ', function(event, arg) {console.log(arg); // output Pong}); ipcRenderer.send('asynchronous-message', 'ping');The menu module
The Menu module can be used to create native menus, which can be used as application menus and content menus.
Example:
Create a new menu syntax:
var menu = new Menu();MenuItem module
The MenuItem module adds menu subitems to the back and forth menu.
Example:
Create a new MenuItem syntax:
var menuItem = new MenuItem(options)Options options look like this:
clickroletypelabelsublabelacceleratoriconenabledvisiblecheckedsubmenuidposition
PowerMonitor module
The PowerMonitor module is used to listen for changes in the energy sector and can only be used in the main process. The app module cannot be used after the ready event is triggered.
Example:
App. on('ready', function() {require('electron').powermonitor. on('suspend', function() {console.log(' The system will go to sleep '); }); });The PowerMonitor object fires the following events:
| The event | describe |
|---|---|
| suspend | Triggered when the system is suspended |
| resume | Triggered while system recovery continues to work |
| on-ac | Triggered when the system is using alternating current |
| on-battery | Triggered when the system is using battery power |
PowerSaveBlocker module
The PowerSaveBlocker module is designed to prevent the application from going into sleep mode, thus allowing the application to keep the system and screen working.
Example:
const powerSaveBlocker = require('electron').powerSaveBlocker;
var id = powerSaveBlocker.start('prevent-display-sleep');
console.log(powerSaveBlocker.isStarted(id));
powerSaveBlocker.stop(id);The PowerMonitor module has the following methods:
| methods | describe |
|---|---|
| start | It starts to stop the system from going into sleep mode |
| stop | To specifyblockerStop the active |
| isStarted | returnboolean, whether the correspondingpowerSaveBlockerHas been launched |
The protocol module
The protocol module can register a custom protocol or use an existing protocol. This module is only available after the app module’s ready event is triggered.
Example:
Using a protocol similar to the file:// functionality:
const electron = require('electron'); const app = electron.app; const path = require('path'); app.on('ready', function() { var protocol = electron.protocol; protocol.registerFileProtocol('atom', function(request, callback) { var url = request.url.substr(7); callback({path: path.normalize(__dirname + '/' + url)}); }, function (error) {if (error) console.error(' protocol failed ')}); });The session module
The session module can be used to create a new session object.
Example:
const BrowserWindow = require('electron').BrowserWindow;
var win = new BrowserWindow({ width: 800, height: 600 });
win.loadURL("http://github.com");
var ses = win.webContents.session;WebContents module
WebContents is an EventEmitter that renders and controls a web page and is a property of a BrowserWindow object.
Example:
const BrowserWindow = require('electron').BrowserWindow;
var win = new BrowserWindow({width: 800, height: 1500});
win.loadURL("https://www.9xkd.com/");
var webContents = win.webContents;The WebContents object can emit the following events:
| The event | describe |
|---|---|
| did-finish-load | Emit an event when the navigation is complete,onloadThe event is complete |
| did-fail-load | This is something likedid-finish-load, but is issued when the load fails or the load is canceled |
| did-frame-finish-load | When aframeEmit an event when the navigation is complete |
| did-start-loading | whentab 的 spinnerstartspinningwhen |
| did-stop-loading | whentab 的 spinnerThe end of thespinningwhen |
| did-get-response-details | An event is emitted when details about the requested resource are available |
| did-get-redirect-request | When specifyingframeAn event is emitted when the document in the |
| page-favicon-updated | whenpageReceive the iconurlWhen the event is emitted |
| new-window | whenpageRequest open specifiedurlThe event is emitted when the window is opened |
| will-navigate | When a user orpageEmit an event when you want to start navigation |
| did-navigate | Emit an event when a navigation ends |
| did-navigate-in-page | An event is emitted when in-page navigation occurs |
| crashed | Issue an event when the renderer process crashes |
| plugin-crashed | Issue an event when the plug-in process crashes |
| destroyed | whenwebContentsAn event is emitted when it is deleted |
| devtools-opened | Issue an event when the developer toolbar is opened |
| devtools-closed | Issue an event when the developer toolbar is closed |
| devtools-focused | Issue an event when the developer toolbar gets focus or opens |
| certificate-error | When verifying a certificate orurlIssue an event when it fails |
| select-client-certificate | Issue an event when a client certificate is requested |
| login | whenwebContentsIssue an event when you want to do basic validation |
| found-in-page | An event is issued when an in-page search using WebContents. FindInPage is performed and an available value is found |
| media-started-playing | Issue an event when the media starts playing |
| media-paused | Issue an event when the media stops playing |
| did-change-theme-color | whenpageThis is usually due to the introduction of onemetaThe label |
| cursor-changed | An event is emitted when the type of mouse changes |
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