private static void receiveCallback(IAsyncResult ar)
{
TCPState state = (TCPState)ar.AsyncState;
int readbytes = 0;
try
{
readbytes = state.Stream.EndRead(ar);
}
catch
{
readbytes = 0;
}
if (readbytes == 0)
{
Console.WriteLine($"\r\nClient {state.ID} have already disconnect.");
clients.Remove(state.ID);
return;
}
byte[] buf = new byte[readbytes];
Array.Copy(state.Buffer, 0, buf, 0, readbytes);
state.Stream.BeginRead(state.Buffer, 0, state.BufferSize, new AsyncCallback(receiveCallback), state);
string cmd = Encoding.ASCII.GetString(buf);
handle(cmd, state);
}
private static void sendCallback(IAsyncResult ar)
{
TCPState state = (TCPState)ar.AsyncState;
try
{
state.Stream.EndWrite(ar);
}
catch { }
}
private static void connectCallback(IAsyncResult ar)
{
TcpListener listener = (TcpListener)ar.AsyncState;
TcpClient client = listener.EndAcceptTcpClient(ar);
listener.BeginAcceptTcpClient(new AsyncCallback(connectCallback), listener);
if (client != null)
{
TCPState state = new TCPState(client);
state.Stream.BeginRead(state.Buffer, 0, state.BufferSize, new AsyncCallback(receiveCallback), state);
Console.WriteLine($"Client {state.ID} have already connect success，waiting for receive data.");
}
}
private static void handle(string cmd, TCPState state)
{
string key = state.ID;
switch (cmd)
{
case "LON\r":
if (!clients.ContainsKey(key))
{
clients.Add(key, state);
}
break;
case "LOFF\r":
clients.Remove(key);
break;
}
}