Getting Prepared
To use the WinSock control on a network you need two things. A Server, and
a Client. The Server will 'listen' to a specified port, and the client will
attempt to connect to this port. Once a connection is made, data/text/files
can be sent two and fro from both ends.
First, you need to know the IP Address or Computer name of a PC.
If you don't, then continue the tutorial, skipping the Ping part, and I will
show you how.
It does not matter where you run the Server from, so long as you
know this. To check your TCP/IP settings are correct, open a DOS prompt, and
type Ping PC_Name, where PC_Name is the name of the PC, or the IP Address. You
don't have to be at a different PC for this to work. You should get something
like the below:
Pinging 192.168.0.2 with 32 bytes of data:
Reply from 192.168.0.2: bytes=32 time<10ms TTL=128
Reply from 192.168.0.2: bytes=32 time<10ms TTL=128
Reply from 192.168.0.2: bytes=32 time<10ms TTL=128
Reply from 192.168.0.2: bytes=32 time<10ms TTL=128
Ping statistics for 192.168.0.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% lo
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms
If you get this:
Pinging 192.169.0.2 with 32 bytes of data:
Destination host unreachable.
Destination host unreachable.
Destination host unreachable.
Destination host unreachable.
Ping statistics for 192.169.0.2:
Packets: Sent = 4, Received = 0, Lost = 4 (100%
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms
then your IP Address/PC Name is incorrect, or your TCP/IP
protocol is not correctly configured. Refer to your Windows help for information
on how to set it up.
To use the WinSock control, you do not actually need another PC
to be on. You can run both the server and client on the same PC! Throughout this
section, I will presume that this is the case, and therefore, we will have the
server and client code in the same VB project.
To start, create a new project, and then add a reference to the
WinSock control. To do this, click Project|Components..., and check the box next
to the Microsoft WinSock Control.