Question

How can I read from a stream when I don’t know in advance how much data will come in? Right now I just picked a number on a high side (as in code below), but there’s no guarantee I won’t get more than that.

So I read a byte at a time in a loop, resizing array each time? Sounds like too much resizing to be done :-/

TcpClient tcpclnt = new TcpClient();
tcpclnt.Connect(ip, port);

Stream stm = tcpclnt.GetStream();

stm.Write(cmdBuffer, 0, cmdBuffer.Length);

byte[] response = new Byte[2048];
int read = stm.Read(response, 0, 2048);

tcpclnt.Close();

Answer 1

Putting it all together, assuming you’re not getting a HUGE (more than can fit into memory)amount of data:

TcpClient tcpclnt = new TcpClient();
tcpclnt.Connect(ip, port);
Stream stm = tcpclnt.GetStream();
stm.Write(cmdBuffer, 0, cmdBuffer.Length);
MemoryStream ms = new MemoryStream();
byte[] buffer = new Byte[2048];
int length;
while ((length = stm.Read(buffer, 0, buffer.Length)) > 0)
    ms.Write(buffer, 0, length);
tcpclnt.Close();
byte[] response = ms.ToArray();

As mentioned the MemoryStream will handle the dynamic byte array allocation for you. And Stream.Read(byte[], int, int) will return the length of the bytes found in this ‘read’ or 0 if it’s reached the end.