Palm OS Network Programming

Sample Application

In this chapter, we extend FtpView to connect with an FTP server. There are minimal changes to our application’s functionality. We can connect to and disconnect from an FTP server, but we still can’t see anything on that server. We have crossed a great divide—our application has connected with a process running on a remote host.

Application Startup

When you first launch FtpView, it initializes the Net Library. This gives us the initial screen as shown in Figure 8-3.

Figure 8-3. Initial screen

The screen has one visible button, the “Connect” button. The user selects this button to initiate a socket connection.

Connecting the Socket

When the user selects the Connect button, the application presents a dialog in which the user to enters the FTP server’s hostname. Figure 8-4 shows this dialog.

Figure 8-4. Connect dialog

The user enters a hostname, and we attempt to connect with the host’s FTP service using the TCP protocol. Figure 8-5 shows the screen after a connection has been made.

Figure 8-5. Completed connection screen

We see the resources consumed by the connection as well as the addresses of the two end-points.

Disconnecting the Socket

In Chapter 9, we exchange data ...