SerialPort CurrentPort = null

current port = new serial port()；

Current port. read buffer size = 128；

Current port. PortName = comName// port number

Current port. BaudRate = bandRate// bit rate

Current port. Parity = parity; //parity check

Current port. StopBits = stop; //Stop bit

Current port. Data bits = data bits; //data bits

Current port. read time out = 1000； //Read timeout, that is, if no data is read within 1000, it will cause timeout exception.

//Bind the data receiving event, because sending is passive, so you can't take the initiative to get the code sent by others, and you can only handle it through this event.

Current port. data received+= Sp _ data received；

Current port. open()；

Define a variable byte[]receiveStr；;

//Bind the event handler

Private static void sp _ datareceived (object sender, system. IO . ports . serial datareceivedeventargs e)

{

serial port sp = sender as serial port；

if (sp == null)

Return;

Byte[] readBuffer = new byte [sp. read buffer size]；

Species Read(readBuffer, 0, readBuffer. Length);

//assignment

ReceiveStr = readBuffer// byte[] can of course be converted into a string by conversion.

}

//The button event you requested can be written like this.

Private void button 1_Click (object sender, EventArgs e)

{

if(receiveStr！ = empty)

{

Variable xxx = receiveStr

}

}