c# 读取串口——如何全部读取

public byte[] Read()
{
byte[] inbuffer = null;
if (serialPort.IsOpen && serialPort.BytesToRead > 0)
{
try
{
inbuffer = new byte[serialPort.BytesToRead];
serialPort.Read(inbuffer, 0, serialPort.BytesToRead);
string strRaad = ASCIIEncoding.ASCII.GetString(inbuffer, 0, inbuffer.Length);

while (strRaad.Contains(serialPort.NewLine))
{
Thread.Sleep(800);
if (serialPort.BytesToRead == 0)
break;
byte[] temp = inbuffer;
byte[] inbuffer2 = new byte[serialPort.BytesToRead];

serialPort.Read(inbuffer2, 0, serialPort.BytesToRead);
inbuffer = new byte[inbuffer.Length + inbuffer2.Length];

temp.CopyTo(inbuffer, 0);
inbuffer2.CopyTo(inbuffer, temp.Length);
strRaad = ASCIIEncoding.ASCII.GetString(inbuffer, 0, inbuffer.Length);
}
}
catch
{
}
}
return inbuffer;
}