Question

C#一个串口发送数据,另一个串口马上接收相同的数据，怎么操作

Answer 1

同一台机只能有一个程序打开串口，自发自收的串口数据，可以将串口的2、3针脚短接，然后再对串口写数据，同时再读串口即可，读写串口可参看MSDN， system.io.ports.serialport 的C#代码
public static void Main()
{
string name;
string message;
StringComparer stringComparer = StringComparer.OrdinalIgnoreCase;
Thread readThread = new Thread(Read);

// Create a new SerialPort object with default settings.
_serialPort = new SerialPort();

// Allow the user to set the appropriate properties.
_serialPort.PortName = SetPortName(_serialPort.PortName);
_serialPort.BaudRate = SetPortBaudRate(_serialPort.BaudRate);
_serialPort.Parity = SetPortParity(_serialPort.Parity);
_serialPort.DataBits = SetPortDataBits(_serialPort.DataBits);
_serialPort.StopBits = SetPortStopBits(_serialPort.StopBits);
_serialPort.Handshake = SetPortHandshake(_serialPort.Handshake);

// Set the read/write timeouts
_serialPort.ReadTimeout = 500;
_serialPort.WriteTimeout = 500;

_serialPort.Open();
_continue = true;
readThread.Start();

Console.Write("Name: ");
name = Console.ReadLine();

Console.WriteLine("Type QUIT to exit");

while (_continue)
{
message = Console.ReadLine();

if (stringComparer.Equals("quit", message))
{
_continue = false;
}
else
{
_serialPort.WriteLine(
String.Format("<{0}>: {1}", name, message) );
}
}

readThread.Join();
_serialPort.Close();
}

public static void Read()
{
while (_continue)
{
try
{
string message = _serialPort.ReadLine();
Console.WriteLine(message);
}
catch (TimeoutException) { }
}
}