ipcRenderer

从渲染器进程到主进程的异步通信。

进程: Renderer

ipcRenderer 是一个 EventEmitter 的实例。 你可以使用它提供的一些方法从渲染进程 (web 页面) 发送同步或异步的消息到主进程。 也可以接收主进程回复的消息。

请从 ipcMain 查看代码示例。

方法

ipcRenderer 模块使用以下方法来监听事件和发送消息。

ipcRenderer.on(channel, listener)

• channel String
• listener Function
  • event IpcRendererEvent
  • ...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。

ipcRenderer.once(channel, listener)

• channel String
• listener Function
  • event IpcRendererEvent
  • ...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.

ipcRenderer.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。

ipcRenderer.removeAllListeners(channel)

• channel String

移除所有的监听器，当指定 channel 时只移除与其相关的所有监听器。

ipcRenderer.send(channel, ...args)

• channel String
• ...args any[]

通过channel向渲染器进程发送异步消息，可以发送任意参数。 Arguments will be serialized with the Structured Clone Algorithm, just like [window.postMessage][], so prototype chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will throw an exception.

NOTE: Sending non-standard JavaScript types such as DOM objects or special Electron objects is deprecated, and will begin throwing an exception starting with Electron 9.

The main process handles it by listening for channel with the ipcMain module.

If you need to transfer a [MessagePort][] to the main process, use ipcRenderer.postMessage.

If you want to receive a single response from the main process, like the result of a method call, consider using ipcRenderer.invoke.

ipcRenderer.invoke(channel, ...args)

• channel String
• ...args any[]

Returns Promise<any> - Resolves with the response from the main process.

Send a message to the main process via channel and expect a result asynchronously. Arguments will be serialized with the Structured Clone Algorithm, just like [window.postMessage][], so prototype chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will throw an exception.

NOTE: Sending non-standard JavaScript types such as DOM objects or special Electron objects is deprecated, and will begin throwing an exception starting with Electron 9.

The main process should listen for channel with ipcMain.handle().

例如：

// Renderer process
ipcRenderer.invoke('some-name', someArgument).then((result) => {
  // ...
})
// Main process
ipcMain.handle('some-name', async (event, someArgument) => {
  const result = await doSomeWork(someArgument)
  return result
})

If you need to transfer a [MessagePort][] to the main process, use ipcRenderer.postMessage.

If you do not need a response to the message, consider using ipcRenderer.send.

ipcRenderer.sendSync(channel, ...args)

• channel String
• ...args any[]

返回 any - 由 ipcMain 处理程序发送过来的值。

Send a message to the main process via channel and expect a result synchronously. Arguments will be serialized with the Structured Clone Algorithm, just like [window.postMessage][], so prototype chains will not be included. Sending Functions, Promises, Symbols, WeakMaps, or WeakSets will throw an exception.

NOTE: Sending non-standard JavaScript types such as DOM objects or special Electron objects is deprecated, and will begin throwing an exception starting with Electron 9.

主进程可以使用 ipcMain 监听 channel来接收这些消息，并通过 event.returnValue 设置回复消息。

⚠️ WARNING: Sending a synchronous message will block the whole renderer process until the reply is received, so use this method only as a last resort. It’s much better to use the asynchronous version, invoke().

ipcRenderer.postMessage(channel, message, [transfer])

• channel String
• message any
• transfer MessagePort[] (optional)

Send a message to the main process, optionally transferring ownership of zero or more [MessagePort][] objects.

The transferred MessagePort objects will be available in the main process as MessagePortMain objects by accessing the ports property of the emitted event.

例如：

// Renderer process
const { port1, port2 } = new MessageChannel()
ipcRenderer.postMessage('port', { message: 'hello' }, [port1])
// Main process
ipcMain.on('port', (e, msg) => {
  const [port] = e.ports
  // ...
})

For more information on using MessagePort and MessageChannel, see the MDN documentation.

ipcRenderer.sendTo(webContentsId, channel, ...args)

• webContentsId Number
• channel String
• ...args any[]

Sends a message to a window with webContentsId via channel.

ipcRenderer.sendToHost(channel, ...args)

• channel String
• ...args any[]

就像 ipcRenderer.send，不同的是消息会被发送到 host 页面上的 <webview> 元素，而不是主进程。

事件对象

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