public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
// There might be more data, so store the data received so far.
state.sb.Append(Encoding.ASCII.GetString(
state.buffer, 0, bytesRead));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("?") > -1)
{
// All the data has been read from the
// client. Display it on the console.
content = content.Substring(0, content.Length - 1);
// Echo the data back to the client.
Expression expression = JSONHelper.From <AsyncSocketServer.Expression>(content);
Console.WriteLine("Calculating : {0} ... ", expression.argument1 + expression.oper + expression.argument2);
String result = null;
try{
double val = expression.eval();
result = val.ToString();
}catch (InvalidOperationException ex) {
result = ex.Message;
}
Send(handler, result);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
