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ActiveXperts.com » Network Component » How to Use Network Component » Telnet » Delphi

Delphi Telnet Sample Source Code

Network Component provides an easy-to-use development interface to a variety of IP protocols. By using Network Component, you can very easily create or enhance applications with network features.

Network Component features the following: DNS, FTP, HTTP, HTTPs, ICMP Ping, IP-to-Country, MSN, NTP, RSH, SCP, SFTP, SNMP v1/v2c (Get, GetNext, Set), SNMP Traps, SNMP MIB, SSH, TCP, Telnet, TFTP, UDP, Telnet, Wake-On-LAN and more.

Network Component can be well integrated into any development platform that supports ActiveX objects.



Step 1: Download and install the Network Component

Download Network Component from the ActiveXperts Download Site and start the installation. The installation guides you through the installation process.

Step 2: Create a new Delphi Project

Launch Borland Delphi from the Start menu. Choose 'New' from the 'File' menu and select your preferred kind of application, for instance: 'VCL Forms Application - Delphi for Win32'. A new Form is displayed in the workspace.

Step 3: Refer to the Network Component Library and create the objects

Now that a new project has been created, you must add a reference to Network Component in the project to be able to use the Network Component object. To do so, choose 'Import Component...' from the 'Component' menu. The Import Components' dialog appears. Select 'Import a Type Library':

Borland Delphi

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In the 'Registered Type Libraries' page, select 'Network Component 4.4 Type Library' and click 'Next':

Borland Delphi

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In the 'Components' page, leave all fields default and click 'Next':

Borland Delphi

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In the 'Install' page, select 'Create Unit' and click 'Next':

Borland Delphi

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The interface code is generated now and is shown in the AxNetwork_TLB tab of the project.

Step 4: Declare and create the object

From the Project Manager, open Unit1.bas and add the AxNetwork_TLB to the 'Uses' statement to refer to the Network Component library:

Delphi

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In the 'private' or 'public' section, declare the following objects:

Appendix: Full source code

program TelnetDemo;

{$APPTYPE CONSOLE}

uses
 SysUtils, ActiveX,
 AxNetwork_TLB in '../../Imports/AxNetwork_TLB.pas';

{==============================================================================}
{==============================================================================}
{= T H E   P R O G R A M   I T S E L F ========================================}
{==============================================================================}
{==============================================================================}
var
 objTCP:Tcp;
 objConstants:NwConstants;
 strHost:string;
 strReceived:string;
 numPort:integer;

begin
 CoInitialize(nil);

 strHost := 'www.activexperts.com';
 strReceived := '';
 numPort := 80;

 objTCP := COTcp.Create();
 objConstants := CONwConstants.Create();

 objTCP.Protocol:= objConstants.nwSOCKET_PROTOCOL_TELNET;

 // To enable logging,assign a valid log file to the LogFile property
 // objTcp.LogFile := 'C:\TelnetDemo.log';

 // Make a connection to remote server
 objTcp.Connect( strHost, numPort );
 WriteLn('Connect( ' + strHost + ', ' + IntToStr(numPort) + ' ), result: ' + IntToStr(objTcp.LastError) + ' (' + objTcp.GetErrorDescription(objTcp.LastError) + ')' );

 if( objTcp.LastError = 0)and(objTcp.ConnectionState = objConstants.nwSOCKET_CONNSTATE_CONNECTED )then
  begin
   // YES, connection established.
	 WriteLn('Connection established');

	 objTcp.Sleep( 1000 );

	 objTcp.SendString('GET /network-component/demopage/ HTTP/1.1');
	 objTcp.SendString('Host: www.activexperts.com');
	 objTcp.SendString('');

   objTcp.Sleep( 1000 );

	 if( objTcp.HasData() = true )then
    begin
		 strReceived := objTcp.ReceiveString();
		 WriteLn('RECV: ' + strReceived );
    end;
   objTcp.Sleep( 1000 );
  end;

 // And finally, disconnect
 objTcp.Disconnect();
 WriteLn('Disconnect, result: ' + IntToStr(objTcp.LastError) + ' (' + objTcp.GetErrorDescription(objTcp.LastError) + ')' );


 WriteLn('Ready.');
 sleep(3000);
 writeln('Done. Press  to close this window');readln;
end.

You can download the complete samples here. There are many other working Network Component scripts on our site and shipped with the product.