a fresh-girl with puzzle dom

Question

it about serial COM port communications with MSComm,i used ' do{...}while ' to instead of OnComm event,example: byte[] inDate; do { System.Windows.Forms.Application.DoEvents(); }while(com.InBufferCount==0); byte[] inData=new byte[com.inBufferCount]; inDate=(byte[])com.Input; my program is that recieve one byte and send one byte to confirm communication is correct,then recieve the last 292 bytes, but why when the device send bytes to com, the indate only can find 8 bytes?