'message' 事件

• message <Object> | <boolean> | <number> | <string> | <null> 解析的 JSON 对象或可序列化的原始值。
• sendHandle <net.Server> | <net.Socket> net.Server 或 net.Socket 对象、或未定义。

如果 Node.js 进程是使用 IPC 通道衍生（参见子进程和集群文档），则每当子进程收到父进程使用 childprocess.send() 发送的消息时，就会触发 'message' 事件。

消息经过序列化和解析。 结果消息可能与最初发送的消息不同。

如果在衍生进程时将 serialization 选项设置为 advanced，则 message 参数可以包含 JSON 无法表示的数据。 有关更多详细信息，请参阅子进程的高级序列化。

• message <Object> | <boolean> | <number> | <string> | <null> a parsed JSON object or a serializable primitive value.
• sendHandle <net.Server> | <net.Socket> a net.Server or net.Socket object, or undefined.

If the Node.js process is spawned with an IPC channel (see the Child Process and Cluster documentation), the 'message' event is emitted whenever a message sent by a parent process using childprocess.send() is received by the child process.

The message goes through serialization and parsing. The resulting message might not be the same as what is originally sent.

If the serialization option was set to advanced used when spawning the process, the message argument can contain data that JSON is not able to represent. See Advanced serialization for child_process for more details.