ISerialSendingPluginOnSerialSending 方法
            在串行数据发送前触发的事件处理程序
            
命名空间: TouchSocket.SerialPorts程序集: TouchSocket.SerialPorts (在 TouchSocket.SerialPorts.dll 中) 版本:4.0.0-beta.143+5fcca7a4e70968794985dc3793adc50531308be6
Task OnSerialSending(
	ISerialPortSession client,
	SendingEventArgs e
)
Function OnSerialSending ( 
	client As ISerialPortSession,
	e As SendingEventArgs
) As Task
abstract OnSerialSending : 
        client : ISerialPortSession * 
        e : SendingEventArgs -> Task 
- client  ISerialPortSession
 - 串行端口会话客户端
 - e  SendingEventArgs
 - 发送事件参数
 
Task异步任务