c# serialport读取不限数量的16进制数据

//private char[] HexChar = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };

private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
char hexH;
char hexL;
byte receivebyte;
string dataToshow = "";
while (serialPort1.BytesToRead > 0)
{
receivebyte = (byte)serialPort1.ReadByte();
hexH = HexChar[receivebyte / 16];
hexL = HexChar[receivebyte % 16];
dataToshow += hexH.ToString() + hexL.ToString();
}
this.tBox.Invoke(new MethodInvoker(delegate
{
this.tBox.AppendText(dataToshow + "\n");
}));
}