Creating the Client
In the sample provided with this article, we are going to create two applications,
one server and client. This is a real world example, where the clients requests
some information from the server and the server retrieves some specific information
from the database and sends the retrieved information back to the client. The
database used in the sample is also provided with the code. The database name
is Prices.mdb. This is a small database comprising of a single table containing
two fields. The fields are item number and price. The clients sends the item
number to the server and the server retrieves the price against that item number
from the database and sends it back to the client. One of the current trends
in software development today is the issue of thick clients versus thin clients.
A thick client is basically an application that performs the bulk of the processing
on the individual client PC, whereas a thin client performs the processing on
the server.
Creating the Client
Follow the steps shown below:
1. Start a new EXE project.
2. Add a Winsock control to your application.
3. Add all the controls to the form (See the application for details).
Here is the complete code:
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Option Explicit
Private Sub cmdClose_Click()
Winsock1.Close
shpGo.Visible = False
shpWait.Visible = False
shpError.Visible = True
End Sub
Private Sub cmdConnect_Click()
Winsock1.RemoteHost = "11.0.0.1" 'Change
this to your host ip
Winsock1.RemotePort = 1007
Winsock1.Connect
shpGo.Visible = True
txtItem.SetFocus
End Sub
Private Sub cmdSend_Click()
If Winsock1.State = sckConnected Then
Winsock1.SendData txtItem.Text
shpGo.Visible = True
Label3.Caption = "Sending
Data"
Else
shpGo.Visible = False
shpWait.Visible = False
shpError.Visible = True
Label3.Caption = "Not
currently connected to host"
End If
End Sub
Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
Dim sData As String
Winsock1.GetData sData, vbString
'Label1.Caption = sData
txtPrice.Text = sData
Label3.Caption = "Received Data"
shpGo.Visible = True
shpWait.Visible = False
shpError.Visible = False
End Sub
Private Sub Winsock1_SendComplete()
Label3.Caption = "Completed Data Transmission"
End Sub
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