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ipcMain

Comunica de forma assíncrona o processo principal aos processos de renderização.

Process: Main

O módulo ipcMain é um emissor de eventos. Quando usado no processo principal, ele lida com mensagens assíncronas e síncronas enviadas a partir de um processo de renderização (página da web). As mensagens enviadas de um renderizador serão emitidas para este módulo.

For usage examples, check out the IPC tutorial.

Sending messages

It is also possible to send messages from the main process to the renderer process, see webContents.send for more information.

  • Ao enviar uma mensagem, o nome do evento é o channel.
  • Para responder a uma mensagem síncrona, você precisa de configurar event.returnValue.
  • Para enviar uma mensagem assíncrona de volta para o remetente, você pode usar event.reply(...). 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.

Métodos

The ipcMain module has the following methods to listen for events:

ipcMain.on(channel, listener)

  • channel string
  • listener Função

Ouve o channel, quando uma mensagem chega, o listener deve ser chamado com listener(event, args...).

ipcMain.off(channel, listener)

  • channel string
  • listener Função

Removes the specified listener from the listener array for the specified channel.

ipcMain.once(channel, listener)

  • channel string
  • listener Função

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.addListener(channel, listener)

  • channel string
  • listener Função

Alias for ipcMain.on.

ipcMain.removeListener(channel, listener)

  • channel string
  • listener Função
    • ...args any[]

Alias for ipcMain.off.

ipcMain.removeAllListeners([channel])

  • channel string (opcional)

Removes all listeners from the specified channel. Removes all listeners from all channels if no channel is specified.

ipcMain.handle(channel, listener)

  • channel string
  • listener Function<Promise<any> | 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.

Errors thrown through handle in the main process are not transparent as they are serialized and only the message property from the original error is provided to the renderer process. Please refer to #24427 for details.

ipcMain.handleOnce(channel, listener)

  • channel string
  • listener Function<Promise<any> | 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.