[NumLock]

вариант 1:

Код:

procedure TForm1.ServerSocket1ClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
var
  len: Integer;
  buf: array of Char;
  i: Integer;
begin
  len:=Socket.ReceiveLength;
  SetLength(buf, len);
  Socket.ReceiveBuf(buf[0], len);
  for i:=0 to len-1 do
  begin
    // buf[i]
  end;
end;

вариант 2:

Код:

procedure TForm1.ServerSocket1ClientRead(Sender: TObject;
  Socket: TCustomWinSocket);
var
  len: Integer;
  buf: PChar;
begin
  len:=Socket.ReceiveLength;
  buf:=GetMemory(len);
  try
    Socket.ReceiveBuf(buf^, len);
//    Memo1.Lines.Add(Copy(buf, 1, len));
  finally
    FreeMemory(buf);
  end;
end;