Flash MX 2004 Games : Art to ActionScript

Chapter 22: Multi-player games using sockets
is set. For the SockListener application we want to initialize a server socket. The dialog will only
ever contain one of these, but first we need the IP address of the server. To get this we create a
function called ‘GetServerIP’. This uses the API (Application Programming Interface) function,
‘gethostname’. The purpose of this function is to return the host name in string format. Notice
that unlike Flash, every variable has to be of a specified type, and every variable must be declared
before use.
After getting the name of the server, a structure HOSTENT is returned using the function
‘gethostbyname’ passing the host name as a parameter. The HOSTENT structure contains details
about the server including the IP address, which is stored in the member h_addr. The host name
is stored in the member variable ‘m_cshostname’ for future use.
1 BOOL CSockListenerDlg::GetServerIP()
2 {
3 HOSTENT *hs;
4 UCHAR ch[4]={0};
5
6
CString csInfo;
7 ::gethostname((LPSTR)(LPCTSTR)m_cshostname, 50);
8
9
hs = gethostbyname((LPSTR)(LPCTSTR)m_cshostname);
10 memcpy(ch, hs->h_addr, 4);
11 csInfo.Format("%s %d.%d.%d.%d", m_cshostname,
12 ch[0], ch[1], ch[2], ch[3]);
13
14
GetDlgItem(IDC_TEXT)->SetWindowText(csInfo);
15
16 }
return TRUE;
Listing 22.1
Assuming that the IP address was successfully found, the server socket is created using the PORT
defined by the constant PORT; in this example this is set to 5001 and the fact that the type of
socket is a stream. The value of the PORT is set in file ‘stdafx.h’ which is part of this application
and the value for the constant SOCK_STREAM is defined in the file ‘winsock.h’ which is a
standard file included with Visual C++. Having created the server socket it is set to listening mode
using the member function ‘Listen’.
1 ////////////////////////////////////////////////////////////////////
2 //
3 // CSockListenerDlg message handlers
4
5 BOOL CSockListenerDlg::OnInitDialog()
6 {
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