c# - How to read data from serial port and write to serial port? -

hi i'm writing application in c# connect device via rs232(com) port. need send "read" command read data , "write" command send data it.

i read articles in here , other sites , know there methods when i'm defining serial port in c#.

but question ,should concerned dtr ,rts ,... ? for? how use them?

just give idea simple function writes command byte array on serial , reads corresponding input serial port (in example read fourth byte of value read serial port):

private string readfromserial() {     try     {         system.io.ports.serialport serial1 = new system.io.ports.serialport("com1", 9600, system.io.ports.parity.none, 8, system.io.ports.stopbits.one);         serial1.dtrenable = true;         serial1.rtsenable = true;         serial1.readtimeout = 3000;          var messagebufferrequest = new byte[8] { 1, 3, 0, 28, 0, 1, 69, 204 };         var messagebufferreply = new byte[8] { 0, 0, 0, 0, 0, 0, 0, 0 };         int bufferlength = 8;          if (!serial1.isopen)         {             serial1.open();         }          try         {             serial1.write(messagebufferrequest, 0, bufferlength);         }         catch (exception ex)         {             logex(ex);             return "";         }          system.threading.thread.sleep(100);          serial1.read(messagebufferreply, 0, 7);          return messagebufferreply[3].tostring();     }     catch (exception ex)     {         logex(ex);         return "";     } }