dgram.createSocket(options[, callback])

• options <Object> 允许的选项是:
  • type <string> 套接字族. 必须是 'udp4' 或 'udp6'。必需填。
  • reuseAddr <boolean> 若设置为 true，则 socket.bind() 会重用地址，即使另一个进程已经在其上面绑定了一个套接字。默认值: false。
  • ipv6Only <boolean> 将 ipv6Only 设置为 true 将会禁用双栈支持，即绑定到地址 :: 不会使 0.0.0.0 绑定。默认值: false。
  • recvBufferSize <number> 设置 SO_RCVBUF 套接字值。
  • sendBufferSize <number> 设置 SO_SNDBUF 套接字值。
  • lookup <Function> 自定义的查询函数。默认值: dns.lookup()。
• callback <Function> 为 'message' 事件绑定一个监听器。可选。
• 返回: <dgram.Socket>

创建一个 dgram.Socket 对象。 一旦创建了套接字，调用 socket.bind() 会指示套接字开始监听数据报消息。 如果 address 和 port 没传给  socket.bind()，那么这个方法会把这个套接字绑定到 "全部接口" 地址的一个随机端口（这适用于 udp4 和 udp6 套接字）。 绑定的地址和端口可以通过 socket.address().address 和socket.address().port 来获取。

• options <Object> Available options are:
  • type <string> The family of socket. Must be either 'udp4' or 'udp6'. Required.
  • reuseAddr <boolean> When true socket.bind() will reuse the address, even if another process has already bound a socket on it. Default: false.
  • ipv6Only <boolean> Setting ipv6Only to true will disable dual-stack support, i.e., binding to address :: won't make 0.0.0.0 be bound. Default: false.
  • recvBufferSize <number> Sets the SO_RCVBUF socket value.
  • sendBufferSize <number> Sets the SO_SNDBUF socket value.
  • lookup <Function> Custom lookup function. Default: dns.lookup().
• callback <Function> Attached as a listener for 'message' events. Optional.
• Returns: <dgram.Socket>

Creates a dgram.Socket object. Once the socket is created, calling socket.bind() will instruct the socket to begin listening for datagram messages. When address and port are not passed to socket.bind() the method will bind the socket to the "all interfaces" address on a random port (it does the right thing for both udp4 and udp6 sockets). The bound address and port can be retrieved using socket.address().address and socket.address().port.