ipcMain

从主进程到渲染进程的异步通信。

进程：主进程

ipcRenderer 是一个 EventEmitter 的实例。 当在主进程中使用时，它处理从渲染器进程（网页）发送出来的异步和同步信息。 从渲染器进程发送的消息将被发送到该模块。

发送消息

也可以从主进程向渲染进程发送消息，查阅ebContents.send获取更多信息。

• 发送消息时，事件名称为channel。
• 回复同步信息时，需要设置event.returnValue。
• 可以使用event.sender.send(...)将异步消息发送回发送者。 This helper method will automatically handle messages coming from frames that aren’t the main frame (e.g. iframes) whereas event.sender.send(...) will always send to the main frame.

下面是在渲染和主进程之间发送和处理消息的一个例子：

// 在主进程中.
const { ipcMain } = require('electron')
ipcMain.on('asynchronous-message', (event, arg) => {
  console.log(arg) // prints "ping"
  event.reply('asynchronous-reply', 'pong')
})
ipcMain.on('synchronous-message', (event, arg) => {
  console.log(arg) // prints "ping"
  event.returnValue = 'pong'
})

//在渲染器进程 (网页) 中。
const { ipcRenderer } = require('electron')
console.log(ipcRenderer.sendSync('synchronous-message', 'ping')) // prints "pong"
ipcRenderer.on('asynchronous-reply', (event, arg) => {
  console.log(arg) // prints "pong"
})
ipcRenderer.send('asynchronous-message', 'ping')

方法

IpcMain模块有以下方法来侦听事件：

ipcMain.on(channel, listener)

• channel String
• listener Function
  • event IpcMainEvent
  • ...args any[]

监听 channel，当接收到新的消息时 listener 会以 listener(event, args...) 的形式被调用。

ipcMain.once(channel, listener)

• channel String
• listener Function
  • event IpcMainEvent
  • ...args any[]

Adds a one time listener function for the event. This listener is invoked only the next time a message is sent to channel, after which it is removed.

ipcMain.removeListener(channel, listener)

• channel String
• listener Function
  • ...args any[]

从监听器数组中移除监听 channel 的指定 listener。

ipcMain.removeAllListeners([channel])

• channel String (optional)

删除所有监听者，或特指的 channel 的所有监听者.

ipcMain.handle(channel, listener)

• channel String
• listener Function | any>
  • event IpcMainInvokeEvent
  • ...args any[]

Adds a handler for an invokeable IPC. This handler will be called whenever a renderer calls ipcRenderer.invoke(channel, ...args).

If listener returns a Promise, the eventual result of the promise will be returned as a reply to the remote caller. Otherwise, the return value of the listener will be used as the value of the reply.

// Main process
ipcMain.handle('my-invokable-ipc', async (event, ...args) => {
  const result = await somePromise(...args)
  return result
})
// Renderer process
async () => {
  const result = await ipcRenderer.invoke('my-invokable-ipc', arg1, arg2)
  // ...
}

The event that is passed as the first argument to the handler is the same as that passed to a regular event listener. It includes information about which WebContents is the source of the invoke request.

ipcMain.handleOnce(channel, listener)

• channel String
• listener Function | any>
  • event IpcMainInvokeEvent
  • ...args any[]

Handles a single invokeable IPC message, then removes the listener. See ipcMain.handle(channel, listener).

ipcMain.removeHandler(channel)

• channel String

Removes any handler for channel, if present.

IpcMainEvent object

The documentation for the event object passed to the callback can be found in the ipc-main-event structure docs.

IpcMainInvokeEvent object

The documentation for the event object passed to handle callbacks can be found in the ipc-main-invoke-event structure docs.